THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


ORTHODONTIA 


MALPOSITION  OF  THE  HUMAN  TEETH 
ITS  PREVENTION  AND  REMEDY 


BY 

S.  H.  GUILFORD,  A.M.,  D.D.S.,  PH.D. 

Professor  of  Operative  and  Prosthetic  Dentistry  in  the  Philadelphia 
Dental  College;  Author  of  "Nitrous  Oxide,"  Etc. 


Approved    by  the    National  Association  of   Dental  Faculties  as  A 
text-book  for  use  in  the  schools  of  its  representation 


FOURTH     EDITION 


PHILADELPHIA: 

PkKSS  OF  T.  C.   DAVIS  >\   S 

529   COMMKRCK    STRKKT 


Knterecl  according  to  Act  of  Congress,  in  the  year  lun.s,  l>y 

S.  H.  GUILFORD 
In  the  Office  of  the  Librarian  of  Congress,  at  Washington,  D.  C. 


To  Tin; 

MANY  STCDKXTS  WHO  HAVE  SAT  UXDKR  MY  TKACHIXG  DURING  THK  i1  AM 
TWKNTY-FIVE  YEAKS  AND  WHO,  I  TRUST,  HAVK  UEKX  INSPIRED 

WITH   A  DEEP  INTEREST  IN  THE  SUBJECT  OF   ORTHODONTIA, 

THIS  FOURTH  EDITION  is  KKSPKCTFULLY  INSCKIIIKH. 


This  work  has  been  written  at  the  request  of  the  National 
Association  of  Dental  Faculties  in  furtherance  of  its  plan  to 
secure  the  preparation  of  a  series  of  text  books  for  use  in 
American  Dental  Colleges.  After  its  completion  and  exami- 
nation, it  was  accepted  and  endorsed  by  the  Association  at 
its  meeting  in  Saratoga,  August,  1888. 

The  impartment  of  instruction  in  the  simplest  and  most 
direct  manner  being  the  true  province  of  a  text-book,  the 
author  has  endeavored  in  the  preparation  of  this  work  to 
treat  the  subject  as  concisely  as  possible,  and  to  clothe  his 
thoughts  and  those  of  others  in  such  language  as  to  be 
readily  comprehended  by  beginners  as  well  as  those  some- 
what advanced  in  this  branch  of  study. 

In  the  treatment  of  the  subject  the  aim  has  been  to  lead 
the  student  step  by  step  from  the  simplest  beginnings  to 
the  more  complicated  and  difficult  work  of  practical  treat- 
ment. To  this  end,  the  underlying  principles  of  the  art  are 
first  elucidated,  after  which  the  principal  methods  employed 
are  explained,  and  lastly,  the  correlation  of  principles  and 
methods  is  shown  in  their  practical  application  to  typical 
cases.  In  Part  III,  the  different  forms  of  irregularity, 
together  with  a  variety  of  plans  for  their  correction,  are 
arranged  under  such  headings  and  in  such  order  as  to  be 
readily  referred  to  in  seeking  aid  for  cases  that  occur  in 
office  practice. 

v 


VI  PREFACE 

Should  the  work  fulfill  the  object  aimed  at  in  its  prepa- 
ration, the  author  will  feel  amply  repaid. 

Credit  for  assistance  is  most  cheerfully  given  to  the 
twent3r-five  teachers  of  this  branch  in  American  Dental 
Colleges  who  have  read  this  work  in  manuscript,  and  by 
friendly  criticism  and  valuable  suggestions  added  much  to 
its  completeness. 

The  author  would  also  acknowledge  his  indebtedness  to 
Prof.  W.  F.  Litch  for  valuable  services,  and  to  the  S.  S. 
White  Co. ;  Lea,  Brothers  &  Co. ;  P.  Blakiston,  Son  &  Co. ; 
and  other  publishers  and  authors  for  the  use  of  certain  cuts. 

S.  H.  G. 
Philadelphia,  Sept.,  1889. 


PREFACE  TO  FOURTH  EDITION. 


The  last  or  third  edition  of  this  work  was  one  of  twice  the 
usual  size  and  such  has  been  the  rapid  advancement  along 
the  lines  of  Orthodontia  that  before  the  edition  was  exhausted 
many  of  the  methods  therein  advocated  had  become  obsolete. 

In  view  of  this  the  work  had  to  be  entirley  recast  and 
rewritten  and  most  of  the  old  illustrations  were  obliged 
to  give  way  to  newer  ones,  nearly  all  of  which  are  photo 
engravings. 

Several  entirley  new  chapters  have  been  introduced,  one 
of  which :  "Outline  of  College  Technic  Course"  and  part  of 
another ;  "Construction  of  Appliances"  it  is  hoped  will  be  of 
material  benefit  to  both  teachers  and  students. 

The  author's  new  classification  conforms  to  the  plan 
adopted  in  collateral  sciences  of  grouping  together  types 
possessing  like  characteristics  and  giving  to  each  type  a 
distinctive  name  indicating  the  condition.  By  this  means 
the  entire  subject  is  made  more  clear  and  cases  can  be  readily 
referred  to  their  proper  class. 

A  few  new  terms  have  been  coined  and  introduced  to 
take  the  place  of  cumbersome  expressions  heretofore  in  use. 
Benocclusion,  meaning  normal  occlusion,  harmonizes  with 
its  opposite  Malocclusion,  while  Antocclusion  (ante,  before) 
signifies  occlusion  anterior  to  normal  and  Postocclusion 
(post,  after,  behind),  occlusion  posterior  to  normal.  Another 
Latin  derivative,  Nonocclusion,  though  not  new  to  our 
nomenclature,  expresses  the  condition  so  clearly  that  it 
should  be  generally  adopted. 

The  author  desires  to  express   his   indebtedness   to   his 

vii 


Vlll  PREFACE. 

fellow-teachers,  Profs.  M.  H.  Cryer  and  C.  S.  Case  for  their 
interest  and  assistance,  to  Drs.  Geo.  C.  Ainsworth,  M.  A. 
Knapp,  S.  M.  Weeks,  and  Mr.  J.  E.  Canning  for  loan  of  models 
and  illustrations,  and  to  Dr.  E.  A.  Schwabe  for  valuable 
photographic  work.  The  S.  S.  White  Co.,  Justi  &  Sons,  and 
the  International  Dental  Publication  Co.  have  also  kindly 
lent  their  assistance. 

S.  H.  G. 
Philadelphia,  November,  1905. 


CONTENTS. 


PART  I. 

PRINCIPLES. 

CHAPTER  I. 

I'ACJE. 

DEFINITION  OF  IRRK<U:I,ARITY, 9 

CHAPTER  II. 

ETIOLOGY. 

INJUDICIOUS  EXTRACTION — DELAYED  ERUPTION — SUPERNUMER- 
ARY TEETH  —  ACCIDENTS  —  ADENOIDS  —  HABITS — UPPER 
PROTRUSION — LOWER  PROTRUSION — GOTHIC  ARCH — CON- 
STRICTED ARCH, 12 

CHAPTER   III. 

FACIAL  HARMONY  AND  OCCLUSAL  RELATION. 
HARMONIOUS  RELATION  OF  FEATURES — BENOCCLUSION — MAL- 

OCCLUSION, 30 

CHAPTER  IV. 

CONDITIONS  GOVERNING  CORRECTION. 
AGE — HEALTH — SKX,  ETC., 37 

CHAPTER  Y. 

EXTRACTION. 
RARELY  NECESSARY — WHEN  PERMISSABLE — EVILS  RESULTING 

FROM — RULES  GOVERNING, 42 

ix 


X  CONTENTS. 

CHAPTER  VI. 

PHYSIOLOGY  OF  TOOTH  MOVEMENT  AND  CHARACTER 
OF  TISSUES  INVOLVED. 

PAGK. 

ALVEOLAR  PROCESS — TEETH— PULP — PERICEMENTUM — CHANGES 
DURING  TOOTH  MOVEMENT — CHANGES  SUBSEQUENT  TO  TOOTH 
MOVEMENT, 49 

CHAPTER  VII. 

DYNAMICS  OF  TOOTH  MOVEMENT. 
ANCHORAGE — REINFORCED — RECIPROCAL — INTERMAXILLARY,  .  58 


PART  II. 

PRACTICAL   CONSIDERATIONS. 
CHAPTER  I. 

PRELIMINARIES  AND  STUDY  OF  CASE. 
EXAMINATION  —  IMPRESSIONS  —  MODELS  —  STUDY    OF   CASE — 
AMOUNT  OF  FORCE  REQUIRED — MANNER  OF  APPLYING — 
ESSENTIAL  QUALITIES  OF  AN  APPLIANCE,     ....  74 

CHAPTER  II. 

MATERIALS  AND  CONSTRUCTION  OF  APPLIANCES. 
TOOLS — PREPARATION  OF  MATERIAL — CONSTRUCTION,        .        .  87 

CHAPTER  III. 

STOCK  APPLIANCES  AND  SPECIAL  METHODS. 
ANGLE'S — KNAPP'S — COFFIN'S — JACKSON'S — AIXSWORTH'S,       .  106 

CHAPTER  IV. 
RETAINING  APPLIANCES, 127 

CHAPTER   V. 
OUTLINE  OF  COLLEGE  TECHNIC  COURSE, 134 


CONTENTS. 


XI 


PART    III. 

CLASSES   OF    IRREGULARITIES   AND   PRACTICAL 
TREATMENT. 

DIVISION  I. 

SIMPLE  IRREGULARITIES. 


CLASS  1.  LABIAL  AND  LINGUAL  MALPOSITION, 

CLASS  2.  MESIAL  AND  DISTAL  MALPOSITION,     . 

CLASS  3.  EXTKUSION  AND  INTRUSION, 

CLASS  4.  TORSION, 


I'AGE. 

142 
151 
157 
163 


DIVISION  II. 


COMPLEX  IRREGULARITIES. 


CLASS       I.     MALPOSITION  OF  ANTERIOR  TEETH, 

a.  NORMAL  BUCCAL  OCCLUSION. 

b.  ABNORMAL     ''  " 

i 

CLASS      II.     UPPER  PROTRUSION, 

a.  LOWER  NORMAL. 

b,  LOWER  RETRUDED. 

CLASS    III.    LOWER  PROTRUSION, 

a.  UPPER  NORMAL. 

b.  UPPER  RETRUDED. 

CLASS    IV.  UPPER  RETRUSION — LOWER  NORMAL, 

CLASS     V.  LOWER  RETRUSION — UPPER  NORMAL, 

CLASS    VI.  BIMAXILLARY  PROTRUSION,    . 

CLASS  VII.  NONOCCLUSION,        .... 


/  UNILATERAL. 
(  BILATERAL. 


172 


179 


194 


199 
202 
205 

208 


ORTHODONTIA. 

PART  I.    PRINCIPLES. 


CHAPTER  I. 

^  Orthodontia  is  that  branch  of  dental  science  which  relates 
to  the  prevention  and  the  correction  of  malposition  of  the 
human  teeth  and  related  parts.  While  the  science  is  com- 
paratively new,  the  condition  is  old,  for  in  many  of  the  types 
of  malposition  the  causes  producing  them  must  have  been 
operative  ages  ago  as  well  as  to-day. 

Civilization,  however,  with  its  attendant  evils  of  lessened 
and  impaired  organic  function,  and  its  development  of  the 
mental  faculties  at  the  expense  of  the  physical,  has  made  its 
influence  felt  upon  the  dental  organs  so  that  their  irregu- 
larity of  position  has  increased  along  with  structural  weak- 
ness and  deformity  in  other  portions  of  the  osseous  system. 

Where,  formerly,  irregularity  of  the  teeth  was  regarded  as 
a  minor  and  rather  unimportant  part  of  dental  practice,  the 
scientific  study  of  the  condition  and  the  deviling  of  appli- 
ances for  its  correction  has  advanced  so  rapidly  of  late  years 
as  to  raise  it  to  the  dignity  of  a  distinct  specialty  of  den- 
tistry. 

Once  regarded  with  dread  by  the  general  practitioner  on 
account  of  its  little  understood  conditions  and  the  difficulties 
attending  its  correction  it  has  now,  by  virtue  of  better 
knowledge  and  the  solving  of  its  many  mechanical  prob- 
lems, become  an  interesting  study  and  has  drawn  to  its 
practice  many  of  the  brightest  minds  of  the  profession,  some 
of  whom  devote  to  it  all  of  their  time  and  energy. 

9 


10  ORTHODONTIA. 

Its  growing  importance  has  given  it  a  special  position  in 
the  curriculum  of  dental  colleges,  in  many  cases  constituting 
a  chair  by  itself. 

The  literature  of  orthodontia  has  naturally  increased  with 
its  development  as  a  science,  as  is  witnessed  by  the  many 
volumes  upon  the  subject  which  have  appeared  in  recent 
years  and  the  almost  numberless  monographs  or  papers 
which  have  studded  dental  periodical  literature. 

One  of  the  greatest  advances  in  the  line  of  orthodontic 
practice  has  been  the  recognition  of  those  causes,  which, 
early  in  life  operate  to  produce  dental  deformity,  and 
which,  through  a  proper  understanding  of  them,  can  be 
met  by  such  remedial  measures  as  will  tend  to  render  them 
abortive. 

While  the  treatment  of  irregularities  or  malpositions  of 
the  teeth  will  in  the  future  largely  be  relegated  to  the  spe- 
cialist or  orthodontist,  it  is  important  that  all  practitioners 
should  have  a  good  general  idea  of  the  subject  in  order  that 
early  preventive  measures  may  be  adopted  and  in  many 
cases  the  simpler  forms  of  irregularity  be  corrected. 

Thegeneral  practitioner,if  properly  informed  upon  the  sub- 
ject, can,  at  least,  greatly  aid  the  orthodontist  in  the  supervi- 
sion of  cases,  and  to  this  end  the  dental  college  student  should 
be  thoroughly  taught  the  fundamental  principles  of  the 
science,  be  made  proficient  in  the  construction  of  regulating 
appliances  and  their  various  uses,  and  receive  as  much  in- 
struction as  possible  in  the  management  of  practical  cases  in 
the  college  infirmary. 

The  experience  of  the  author  as  a  teacher  of  this  branch 
has  shown  him  that  students  often  manifest  a  disinclination 
to  become  interested  in  it  owing  to  its  supposed  difficulties, 
but  by  proper  methods  of  teaching  and  clinical  demonstra- 
tion the  interest  of  the  student  can  be  awakened  and 
developed  to  a  surprising  degree. 

Regularity  and  Irregularity  Defined. — The  teeth  of  man 
when  normally  placed  in  the  alveolar  arch  describe  in  out- 


PRINCIPLES.  11 

line  a  parabola  or  semi-ellipse  with  a  slight  flattening  of  the 
curve  in  the  region  of  the  incisor  and  bicuspid  teeth,  and  a 
consequent  tendency  to  angularity  where  the  cuspids  are 
placed.  The  lower  arch  differs  from  the  upper  principally 
in  being  slightly  smaller.  The  teeth  when  thus  placed 
should  be  in  contact,  each  one  touching  its  neighbors  at  the 
most  prominent  points  of  its  approximal  surfaces,  and  with 
the  cusps  or  occluding  surfaces  in  such  position  as  to  prop- 
erly occlude  with  those  in  the  opposite  jaw.  But  even  when 
thus  arranged  they  may  still  be  inharmonious  by  either  too 
great  prominence  or  such  a  lack  of  it  as  to  constitute  a 
decided  deformity.  It  will  thus  be  seen  that  the  term 
irregularity  covers  a  wide  field,  including  not  only  the 
positions  and  arrangement  of  the  teeth  themselves  but  of 
the  alveolar  arches  in  which  they  are  placed  and  the  har- 
monious relation  of  all  of  these  to  the  other  portions  of  the 
facial  anatomy.  Irregularity  as  most  commonly  met  with 
consists  in  a  deviation  from  the  normal  outline  on  the  part 
of  several  or  all  of  the  teeth,  or  in  the  malposition  of  one  or 
more  individual  teeth ;  if  the  latter,  the  tooth  or  teeth 
may  be  found  outside  or  inside  of  the  regular  arch  line  or 
they  may  be  placed  anteriorly  or  posteriorly  to  their  nor- 
mal positions,  or  they  may  be  turned  upon  their  axes. 
Very  frequently  a  tooth  may  be  in  two  of  these  malposi- 
tions at  the  same  time. 

When  found  existing  in  any  of  its  various  forms,  even  the 
simpler  ones,  malposition  or  irregularity  calls  for  imme- 
diate correction.  Its  neglect  means  not  only  a  greater  or  less 
marring  of  the  features  of  the  individual,  but  also,  according 
to  its  degree,  impairment  of  the  function  of  mastication  ;  the 
superinducement  of  caries,  followed  by  earlier  loss  of  the 
teeth;  and,  in  certain  forms,  very  decided  interference  with 
speech. 


CHAPTER  II. 

ETIOLOGY. 

The  causes  responsible  for  malposition  of  the  teeth  or  jaws 
are  doubtless  various,  and  many  of  them,  as  yet,  undeter- 
mined. For  this  reason  any  exact  classification  is  impossi- 
ble but  for  convenience  we  may  divide  the  causes  into  two 
classes  :  Hereditary  and  Acquired. 

HEREDITARY. 

While  we  have  reason  to  believe,  both  from  observation 
and  experience,  that  fully  ninety  per  cent,  of  the  cases 
of  irregularity  with  which  we  meet  are  due  to  causes 
operative  after  the  birth  of  the  individual,  the  remaining 
number  are  probably  due  to  the  inheritance  of  character- 
istics transmitted  from  an  ancestor  either  near  or  remote,  or 
to  prenatal  influences  with  which  we  are  not  familiar. 

Heredity  manifests  itself  most  commonly  by  reproducing 
in  the  offspring  the  physical  characteristics  of  one  or  the 
other  of  the  parents,  although  in  many  cases  we  find  in  the 
same  child  the  physical  resemblance  of  one  parent  with  the 
mental  and  moral  attributes  of  the  other. 

In  other  cases  the  child  may  be  markedly  lacking  in 
resemblance  to  either  parent  but  have  peculiarities  of  form, 
feature  or  gait  which  resemble  those  of  a  grand  parent. 

But  while  the  biological  law  of  transmission  of  character- 
istics is  for  the  main  part  constant  in  its  workings  in  that 
the  entire  individual  is  usually  a  copy  of  his  progenitor, 
many  cases  are  met  with  in  which  only  certain  physical 
characteristics  of  one  parent  are  reproduced  in  one  of  the 
offspring  and  these  are  blended  with  peculiarities  of  the 
other  parent. 

12 


ETIOLOGY.  13 

Protrusion  of  the  upper  incisor  teeth  has  frequently  been 
noticed  in  both  parent  and  child  while  the  opposite  condi- 
tion of  prognathism  has  been  similarly  met  with. 

Even  so  slight  an  abnormity  as  the  misplacement  or  tor- 
sion of  a  particular  tooth  is  not  an  unusual  occurrence  in 
both  parent  and  child. 

The  author  has  personally  known  two  individuals  (unre- 
lated) each  of  whom  had  inherited  a  light  blue  eye  from  one 
parent  and  a  dark  brown  one  from  the  other. 

These  exceptions  to  the  rule  go  to  show  what  may  occur  in 
exceptional  cases  and  as  they  do  at  times  occur  there  would 
seem  to  be  no  valid  reason  why  a  child  should  not  inherit 
the  large  teeth  of  one  parent  with  the  small  jaws  of  the  other 
or  vice  versa. 

In  the  first  instance  we  would  have  either  a  crowding  of 
the  teeth  out  of  their  normal  positions  or  an  unduly  enlarged 
arch,  while  in  the  other  there  would  exist  interdental  spaces 
among  some  or  all  of  the  teeth. 

These  conditions  seem  to  result  more  frequently  from  the 
inter-marriage  of  races  with  widely  differing  characteristics. 

The  Teutons,  Anglo-Saxons  and  Scandinavians  have  large 
frames  and  large  teeth  while  the  Latin  races  have  smaller 
bodies  and  smaller  teeth.  In  the  United  States,  where  mal- 
arrangement  of  the  teeth  seems  to  be  unusually  common  we 
have  constant  intermarriage  of  members  of  the  various 
European  races. 

ACQUIRED. 

Lony  Retention  of  Deciduous  Teeth. — In  accordance  with 
physiological  law,  the  deciduous  teeth  are  intended  to  sub- 
serve the  wants  of  the  child  until  replaced  by  the  permanent 
set.  The  crown  of  the  permanent  tooth  should  occupy  a 
position  beneath  or  adjacent  to  the  root  of  the  deciduous  one 
which  it  is  intended  to  supplant.  Then,  as  the  root  of  the 
temporary  tooth  is  gradually  resorbed,  the  permanent  tooth 
advances  and  finally  occupies  the  position  previously  occu- 
pied by  its  predecessor. 


14 


ORTHODONTIA. 


FlO.  1. 


It  frequently  happens,  however,  that  the  crypt  of  the  per- 
manent tooth  is  situated  at  some  little  distance  from  the 
root  of  its  corresponding  deciduous  one,  and  as  the  new 
tooth  makes  its  way  into  place  it  assumes  a  position  to  the 
side  of  the  deciduous  root.  As  usually  that  part  of  the  root 
is  resorbed  which  is  in  contact  with  the  vascular  covering 
of  the  advancing  crown,  a  portion  of  the  length  of  the  root 
remains  unabsorbed,  and  the  new  crown  is,  in  consequence, 
compelled  to  advance  by  the  side  of  the  root  instead  of 
beneath  it.  The  deciduous  tooth  as  a  result  of  its  only  par- 
tially resorbed  root  remains  firm  in  place  and  the  new  one 

is  erupted 
out  of  its 
proper  posi- 
tion, had 
the  condition 
been  brought 
to  the  atten- 
tion of  the 
dentist  be- 
fore the  new 
crown  ap- 
peared, the 
extraction  of 
the  decidu- 
ous tooth 
would  have 
permitted  the 
advancing 

tooth  to  assume  its  proper  position  in  the  arch  and  irregu- 
larity have  been  prevented.  When  the  permanent  tooth  is 
advancing  out  of  position  the  fact  may  be  recognized  by  the 
unusual  distension  of  the  gum  and  alveolar  plate  beneath, 
and  the  deciduous  tooth,  no  matter  how  firmly  set,  should 
at  once  be  removed.  Even  the  spicula  of  a  deciduous  root 
has  been  found  sufficient  to  deflect  a  permanent  tooth  from 
its  course  during  eruption. 


Result  of  Delayed  Extraction  of  Deciduous  Incisors. 


ETIOLOGY.  15 

Early  Loss  of  Deciduous  Teeth. — That  the  premature  loss 
of  deciduous  teeth  often  prepares  the  way  for  irregularity  of 
the  permanent  set  is  generally  recognized,  but  the  extent  of 
its  importance  and  the  manner  in  which  it  operates  can  best 
be  understood  by  considering  the  physiological  facts  in  the 
case. 

Irregularity  of  the  deciduous  teeth  is  a  condition  seldom 
met  with.  As  a  rule  they  occupy  their  normal  position  in 
an  alveolar  arch  of  proper  size  to  accommodate  them,  and 
this  again  rests  upon  a  jaw  bone  of  suitable  amplitude. 
Thus  jaw,  process  and  teeth  are  harmoniously  correlated. 
As  each  deciduous  tooth  is  lost  it  is  succeeded  by  the  corre- 
sponding permanent  one,  which,  under  normal  conditions, 
will  occupy  the  space  created  by  the  removal  of  its  prede- 
cessor. In  this  way,  one  by  one,  the  permanent  set  should 
make  its  appearance  until  all  of  the  deciduous  teeth  have 
been  supplanted  by  their  permanent  successors. 

The  permanent  teeth  are  all  larger  than  the  corresponding 
ones  of  the  deciduous  set,  with  one  exception — the  second 
bicuspid.  This  being  the  case,  they  require  a  larger  alveo- 
lar arch  and  a  correspondingly  larger  jaw  bone  for  their 
accommodation.  This  nature  furnishes  by  the  slow  process 
of  enlargement  by  interstitial  growth,  which  is  hastened 
and  stimulated  by  the  lateral  pressure  of  the  teeth  as  they 
make  their  way  into  place,  and  afterward.  When  the  first 
permanent  molar  makes  its  appearance  it  is  obliged  to  pro- 
vide sufficient  accommodation  for  itself  by  forcing  its  way 
between  the  deciduous  second  molar  and  the  strong  maxil- 
lary tuberosity  above  or  the  equally  resistant  ramus  below. 
This  pressure  is  felt  by  all  of  the  other  teeth  in  the  arch.  If, 
therefore,  any  of  the  deciduous  molars  should  be  extracted 
at  about  the  fifth  or  sixth  year  as  they  too  often  are  after 
having  been  impaired  by  disease,  the  permanent  molar 
will  move  forward  and  occupy  part  of  the  space  intended 
for  the  bicuspids. 

When  the  permanent  lower  central  incisors  erupt  they 


16  ORTHODONTIA. 

take  positions  lingually  to  the  deciduous  one,  which  soon 
loosen  and  drop  out.  Owing  to  the  fact  that  the  width  of 
these  new  teeth  is  considerably  greater  than  that  of  their 
predecessors,  they  naturally  overlap  to  a  certain  extent  the 
adjoining  deciduous  laterals.  This  overlapping  prevents 
the  centrals  from  moving  forward  into  line  in  the  arch. 
When  the  permanent  laterals  erupt  they  assume  a  position 
by  the  side  of  the  centrals,  and  to  find  accommodation  in 
this  contracted  space  inside  of  the  arch  line  several  or  all  of 
them  are  apt  to  be  crowded  into  irregular  positions. 

FIG.  2. 


Result  of  Premature  Extraction. 

This  condition,  from  the  fact  that  these  teeth  have  erupted 
too  rapidly  to  admit  of  a  corresponding  increase  in  size  of 
the  alveolar  arch,  is  often  regarded  as  a  serious  evil,  and  to 
correct  it,  the  inexperienced  practitioner  will  in  many  cases 
extract  the  temporary  cuspids  which  are  designed  for  reten- 
tion until  years  afterward.  This  additional  space  having 
been  thus  furnished,  the  permanent  incisors  will  move  for- 
ward into  line  and  assume  a  regular  position. 

Later,  when  the  bicuspids  appear,  they  usually  will  find 


ETIOLOGY. 


17 


no  difficulty  in  assuming  places  in  the  arch,  because  their 
predecessors  occupied  a  larger  space  and  because  the  cuspids 
are  missing,  but  from  the  very  abundance  of  the  space  and 
the  pressure  of  the  first  molar  from  behind,  the  bicuspids  will 
very  soon,  if  not  at  once,  be  so  pressed  forward  that  the  first 
bicuspid  will  come  in  contact  with  the  lateral,  leaving  no 
space  for  the  accommodation  of  the  cuspid  when  it  makes 
its  appearance  at  about  the  eleventh  or  twelfth  year. 

Such  being  the  case,  the  cuspid  must  of  necessity  erupt 
outside  or  inside  of  the  normal  arch  line,  and  produce  a 
deformity  both  unsightly  and  hard  to  correct.  See  Fig.  2. 

Had  the  temporary  cuspids  not  been  extracted,  they 
would  have  preserved  space  for  their  successors,  and  the 
inlocked  and  irregular  incisors,  in  the  course  of  time,  by  the 
normal  enlargement  of  the  arch,  and  the  excess  provided 
by  the  removal  of  the  deciduous  molars,  would  have  had 
space  sufficient,  which  nature,  assisted  by  the  pressure  of  the 
tongue,  would  aid  them  in  occupying. 

The  same  condition  is  met  with  in  the  upper  arch,  per- 
haps more  frequently  than  in  the  lower.  Here  the  incisors 
erupt  outside  of  the  arch  line,  and  sometimes  appear  in  an 
irregular  and  crowded  position,  to  correct  which  the  tem- 
porary cuspids  are  often  needlessly  sacrificed,  and  the  same 
train  of  evils  follows. 

It  will  thus  be  seen  that  the  premature  extraction  of  any 
of  the  temporary  teeth,  especially  the  cuspids,  cannot  well 
result  in  other  than  harm  to  the  permanent  ones,  so  far  as 
regularity  is  concerned. 

Injudicious  Extraction  of  Permanent  Teeth. — A  condition 
frequently  met  with  after  all  the  permanent  teeth  have  been 
erupted,  is  one  where  in  the  upper  jaw  the  centrals,  bicuspids 
and  molars  are  all  harmoniously  arranged,  while  the  laterals 
occupy  a  position  inside  of  the  line  of  the  arch  and  the 
cuspids  lie  outside  of  it.  The  condition  is  most  frequently 
brought  about  by  the  premature  extraction  of  one  or  more 
teeth  of  the  temporary  set,  as  described  under  the  last 
heading. 


18  ORTHODONTIA. 

To  remedy  the  difficulty  in  the  easiest  manner,  some 
practitioners  have  at  times  extracted  the  laterals  and  on 
other  occasions  the  cuspids.  The  result  in  each  case  has 
been  an  almost  hopeless  deformity.  The  cuspids  brought 
next  to  the  centrals  oftentimes  gives  to  the  mouth  a  canine 
appearance,  while  with  cuspids  lacking  the  countenance  is 
robbed  of  that  prominence  near  the  angles  of  the  mouth 
so  necessary  to  harmonious  expression. 

Again,  the  permanent  first  molars  of  one  of  the  jaws  are 
often  neglected  until  caries  has  made  serious  inroads  upon 
them,  when  they  are  extracted  as  offending  members.  The 
result  is  that  the  lateral  pressure,  so  necessary  to  proper 
expansion  of  the  process  is  lacking  in  one  jaw,  while  in  the 
other  the  normal  enlargement  continues.  As  a  consequence 
there  is  disparity  as  to  size  between  the  two  jaws,  and  the 
appearance  of  the  individual  is  permanently  marred. 

Delayed  Eruption  of  Permanent  Teeth. — It  sometimes  hap- 
pens, from  causes  not  easily  definable,  that  the  eruption  of 
one  or  more  of  the  permanent  teeth  is  retarded  to  such  a 
degree  that  the  rest  of  the  set  take  positions  in  the  arch  and 
occupy  all  of  the  space.  When  the  tardy  member  is  ready 
to  erupt  there  is  no  place  for  it,  and  it  is  compelled  to  take 
a  position  outside  or  inside  of  the  arch  line.  This  is  apt  to 
occur  more  frequently  with  the  cuspids  than  any  of  the  other 
teeth,  although  it  is  occasionally  met  with  in  the  laterals 
and  bicuspids. 

Supernumerary  Teeth. — Supernumerary  teeth  are  very  fre- 
quently found  occupying  a  position  in  the  arch  before  the 
eruption  of  the  permanent  set,  so  that  when  the  latter  appear 
there  is  insufficient  room  for  some  of  their  number,  and  these 
are  forced  to  assume  an  abnormal  position.  Such  supernu- 
merary teeth  as  appear  in  the  line  of  the  arch  and  in  the 
anterior  part  of  the  mouth  are  usually  small  and  of  the  con- 
ical or  peg-tooth  variety,  and  are  most  frequently  found 
between  the  central  incisors. 


ETIOLOGY. 


19 


FIG.  3  represents  a  case  of  this  kind  in  the  mouth  of  a  boy, 
nine  years  of  age,  in  which  as  a  result  of  the  presence  of  the 
extra  tooth,  the  left  central  is  erupting  at  an  angle  of  90°, 


FIG.  3. 


Supernumerary  in  Position. 
FIG.  4. 


After  Extraction  of  Supernumerary  and  Eruption  of  Central. 

FIG.  4  shows  the  case  later  after  the  extraction  of  the 

supernumerary  and  with  the  permanent  tooth  fully  erupted. 

In    this   case,  fortunately,  it   happened    that   the   space 


20 


ORTHODONTIA. 


between  the  central  and  lateral,  after  the  extraction  of  the 
supernumerary,  was  just  sufficient  to  accommodate  the 
turned  central  so  that  it  was  rotated  into  position  without 
difficulty. 

FIG.  5.  FIG.   5    illustrates 

another  case  more 
serious  in  character. 
It  is  that  of  a  boy, 
fourteen  years  old, 
and  shows  a  general 
jumbling  of  all  of  the 
anterior  teeth  due  to 
the  presence  of  two 
supernumerary  later- 
als of  regular  size 

General  Displacement  caused  by  Supernumerary  Teeth,    and  form. 

Sometimes  the  presence  of  a  supernumerary  tooth  has  no 

other  effect  upon  the  permanent  set  than  to  occupy  part  of 

the  space  in  the  arch  and  separate  the  adjoining  teeth  by  its 

Flo    6  own  width.     Even 

this,  however,  is 
objectionable,  for 
in  most  cases  the 
tooth,  being  ab- 
normal in  form, 
will  have  to  be 
extracted  and  an 
attempt  made  to 
close  the  space 
thus  created. 

FIG.  6  is  an 
instance  of  two 
su  pernurnerary 

Two  Supernumeraries  between  Centrals.  teeth    Situated    be- 

tween  the  upper  central  incisors.  None  of  the  teeth  are 
turned  or  misplaced,  and  but  for  the  presence  of  these  two 
extra  teeth  the  dental  arch  would  be  a  typical  one. 


ETIOLOGY.  21 

Accidents. — An  accidental  injury  to  one  or  more  of  the 
teeth  of  either  set,  whether  resulting  in  their  loss  or  not,  is 
often  responsible  for  an  irregular  condition.  Should  a 
deciduous  tooth  become  devitalized,  as  the  result  of  an  acci- 
dent or  other  cause,  and  alveolar  abscess  supervene,  the 
physiological  act  of  resorption  will  cease,  and  the  succeed- 
ing tooth  in  the  course  of  its  eruption  will  naturally  be 
deflected  from  its  course  and  erupt  in  an  abnormal  position. 

It  has  also  happened  that  a  deciduous  incisor,  through 
a  fall,  has  been  driven  up  into  the  process.  Such  a  mis- 
fortune can  hardly  fail  to  cause  an  injury  to  the  partially 
formed  permanent  tooth  lying  beneath  it.  Should  no  more 
serious  result  follow,  it  will  probably  at  least  divert  the  new 
tooth  from  its  course  and  be  productive  of  irregularity. 

The  author  had  one  such  case  in  his  practice  with  an 
irregularly  placed  permanent  tooth  as  the  result. 

Adenoid  Vegetations. — Within  past  years  the  attention  of 
oral  and  aural  surgeons  has  been  especially  directed  to  the 
ill-effects  resulting  from  the  presence  of  adenoid  vegetations 
in  the  naso-pharynx. 

These  highly  vascular,  glandular  growths  are  often  found 
in  children  as  early  as  the  second  year  of  life,  and  by 
partially  or  wholly  closing  the  posterior  nares,  interfere 
greatly  with  natural  breathing  through  the  nose.  They 
also  frequently  cause  marked  impairment  of  hearing  by 
impinging  upon  or  closing  the  mouth  of  the  Eustachian 
tube. 

It  has  been  noticed  that  their  presence  is  nearly  always 
associated  with,  and  by  inference  productive  of,  a  pinched 
appearance  in  the  superior  maxillary  and  nasal  regions  of 
the  face.  This  condition  is  undoubtedly  due  to  lack  of 
development  of  the  frontal,  sphenoidal  and  ethmoidal 
sinuses  and  the  maxillary  antrum,  which  being  normally  in 
contact  with  the  air,  cease  to  develop  when  breathing 
through  the  nose  is  interfered  with,  resulting  in  altered 
dimensions  of  the  face. 


22  ORTHODONTIA. 

This  lack  of  development  in  the  osseous  structures  con- 
tiguous to  the  oral  cavity  is  very  likely  to  produce  a  high 
and  contracted  vault  associated  with  a  gothic-arch,  and 
such  condition  of  the  vault  and  arch  has  usually  been 
found  in  cases  where  adenoid  growths,  through  lack  of 
discovery,  have  been  allowed  to  remain  through  a  number 
of  years. 

So  serious  are  the  consequences  of  the  prolonged  presence 
of  these  growths  that  they  should  be  discovered  and  removed 
at  the  earliest  possible  moment  in  order  to  avoid  changes  of 
physiognomy  which  may  never  be  capable  of  correction. 

In  all  cases  of  mouth  breathing,  or  where  there  is  the 
least  reason  for  suspecting  the  presence  of  adenoids,  the 
patient  should  be  referred  to  a  laryngologist  for  exarui- 
tion. 

Dr.  W.  A.  Millls*  reports  a  case  in  practice  of  a  boy,  seven 
years  of  age,  in  which  there  was  almost  complete  obstruction 
of  the  nasal  passages  associated  with  pinched  and  contracted 
features,  such  as  are  noticed  in  the  habitual  mouth-breather. 
The  tonsils  were  greatly  enlarged  and  deglutition  both  diffi- 
cult and  painful.  An  examination  revealed  a  perceptible 
contraction  of  the  sides  of  the  arch  and  an  elevation  of  the 
hard  palate.  Adenoid  growths  were  discovered  and  re- 
moved and  the  tonsils  reduced  in  size  by  the  galvano- 
cautery.  Six  months  later  the  tendency  to  contraction  had 
disappeared,  the  palate  and  arch  had  resumed  their  normal 
form  and  the  patient  had  greatly  improved  in  health  and 
appearance. 

Habits. — The  bad  habits  which  young  children  are  apt 
to  acquire  after  they  are  weaned,  such  as  thumb-,  lip-or 
tongue-sucking,  are  important  factors  in  bringing  about  an 
irregular  alignment  of  the  teeth  in  one  or  more  portions  of 
the  arch.  Acquired  early,  while  the  temporary  teeth  are  in 
position  and  firmly  set,  the  habit  will  usually  make  no 
impression  upon  them,  but  if  not  checked  and  allowed  to 
continue  up  to  the  time  of  the  coming  of  the  permanent  set, 

*0hio  Dental  Journal,  September,  1897, 


ETIOLOGY.  23 

as  is  sometimes  the  case,  these  will  generally  be  thrown  out 
of  position  or  so  altered  in  their  relationship  as  to  cause  a 
serious  deformity. 

This  is  readily  accounted  for  when  we  consider  that  the 
erupting  teeth,  seeking  their  position  in  the  arch  and  sur- 
rounded by  newly  formed  and  pliable  alveolar  tissue,  are 
easily  turned  out  of  their  course  by  any  extraneous  force 
exerted  upon  them. 

The  general  results  of  the  triple  habit  are  the  same, 
although  they  vary  in  particulars.  In  thumb-sucking, 
usually  only  two  or  three  of  the  incisors  are  pressed  out  of 
place,  and  the  ones  affected  are  determined  by  the  hand 
used  and  the  position  of  the  thumb  in  the  mouth.  In  lip 
and  tongue-sucking,  owing  to  the  larger  surface  of  the  organ 
employed,  all  of  the  incisors  will  be  affected. 

When  the  position  of  the  thumb  in  relation  to  the  teeth 
forms  less  than  a  right  angle,  the  upper  teeth  will  be  thrown 
out  and  the  lower  ones  in ;  but  when  held  in  a  horizontal 
position,  the  upper  and  lower  teeth  are  not  displaced,  but 
simply  beld  apart.  As  a  result  of  this  the  first  molars 
are  kept  from  present  contact  and  naturally  elongate  until 
in  time  they  come  together.  The  mouth  is  thus  per- 
manently propped  apart  in  front,  and  when  the  second 
molars  erupt  and  come  into  occlusion  the  ill-condition  is 
confirmed.  With  these  eight  firm  teeth  in  contact,  there  is 
no  longer  any  hope  of  the  ten  anterior  ones  elongating 
sufficiently  to  meet,  and  we  have  the  deformity  known 
as  "  anterior  nonocclusion,"  which  is  not  only  a  disfigure- 
ment, but  a  serious  disadvantage  to  the  individual  in  masti- 
cation and  speech.  This  lack  of  anterior  occlusion  is  not 
always  due  to  the  habit  of  thumb-sucking,  for  it  may  some- 
times be  brought  about  by  physical  peculiarities. 

In  lip-sucking  (or  lip-nursing)  the  lower  lip  is  drawn  into 
the  mouth  over  the  lower  teeth  and  held  there  for  varying 
periods  both  day  and  night.  The  result  is  that  by  the  force 
thus  exerted  the  lower  teeth  are  thrown  inward  while  the 


24  ORTHODONTIA. 

upper  ones  are  forced  outward  to  such  an  extent  as  to  give 

them   unnatural   prominence  and  produce  spaces  between 

them. 

Fig.  7  illustrates  this  condition.     The  child  when  brought 

to  the  author  for  consultation,  was  eleven  years  of  age,  and 
FlG  7  a  confirmed  victim  to  the 

habit  of  lip-sucking.  Near- 
ly all  of  the  permanent 
teeth  in  each  jaw  were 
erupted  and  harmoniously 
related,  excepting  the  pro- 
trusion of  the  upper  and 
retrusion  of  the  lower. 

Result  of  Lip-Nursing.  ^he     ^fa    were     brought 

into  proper  position,  the  appearance  of  the  child  greatly 
improved,  and  the  habit,  by  being  made  impossible,  was 
broken  up. 

The  displacement  and  failure  of  occlusion  of  teeth  in  the 
anterior  part  of  the  mouth  are,  however,  not  the  only  evils 
associated  with  this  habit  in  its  three  forms.  In  each  case 
the  jaws  are  held  temporarily  apart  so  that  there  could  be 
no  occlusion  of  the  teeth  when  the  jaws  were  closed  even 
though  they  were  in  normal  position.  This  leaves  the  side 
teeth  free  to  change  their  position  if  any  influence  is  exerted 
to  produce  that  result.  In  the  act  of  sucking,  the  cheeks  are 
drawn  in  and  the  strong  muscular  pressure  thus  brought  to 
bear  upon  the  bicuspids  and  (occasionally)  the  first  molars, 
may  cause  them  to  incline  inward.  In  this  malposition 
they  are  frequently  confirmed  by  the  opportunity  thus  given 
the  other  molar  teeth  to  move  forward,  of  which  they  are 
not  slow  to  take  advantage. 

Upper  Protrusion. — In  this  condition  the  upper  anterior 
teeth  project  forward  and  outward  to  such  an  extent  as  to 
leave  a  space,  more  or  less  great,  between  their  incisal  edges 
and  those  of  the  lower,  thus  producing  a  marked  deformity 
and  giving  to  the  individual  a  slightly  imbecile  expression. 


ETIOLOGY.  25 

The  lower  anterior  teeth,  when  the  jaws  are  closed,  may  rest 
in  contact  with  the  bases  of  the  superior  ones,  or  they  may 
impinge  upon  the  gum  tissue  adjacent. 

In  some  cases  this  deformity  is  but  the  expression  of  a 
tendency  inherited  from  a  progenitor  under  conditions  favor- 
able to  reproduction,  while  in  others  it  may  be,  and  doubt- 
less is,  the  result  of  mechanical  forces  finding  manifestation 
in  the  individual  alone.  Even  if  inherited  it  must  have 
been  the  result  of  such  causes  in  the  individual  with  whom 
it  originated.  In  its  acquired  form,  this  abnormity  may 
be  caused  by  the  slow  eruption  of  the  posterior  teeth,  which 
by  failing  to  come  into  contact  for  a  long  time  permit  of  an 
unusually  long  over-bite  in  the  incisal  region.  The  lower 
incisors  thus  occluding  with  the  upper  ones  near  their  base 
have  a  tendency  to  force  the  latter  forward  and  outward, 
these  movements  being  favored  by  the  thin  plate  of  alveolar 
process  overlying  the  outer  surfaces,  of  their  roots.  As  the 
upper  teeth  move  outward  the  lower  ones,  from  lack  of 
restraint,  elongate  until  their  incisal  edges  occupy  a  plane 
considerably  above  that  of  their  fellows,  oftentimes  fitting 
into  and  irritating  the  soft  tissues  in  the  roof  of  the  mouth. 

The  same  result  is  sometimes  similarly  brought  about 
later  in  life,  when  through  loss  of  several  of  the  side  or 
back  teeth  the  burden  of  mastication  is  thrown  upon  the 
front  ones.  Lack  of  occlusion  posteriorly  and  excessive 
pressure  anteriorly  will  thus  produce  a  deformity  that  did 
not  exist  early  in  life. 

In  some  cases  it  may  also  be  caused  by  the  maleruption 
of  certain  of  the  posterior  teeth,  permitting  them  to  assume 
positions  in  advance  of  or  posterior  to  their  normal  places ; 
such  a  condition  would  tend  to  restrain  the  lower  teeth  from 
pressing  forward,  and  cause  the  upper  ones  to  advance 
unnaturally. 

The  abnormity  appears  exaggerated  in  cases  where 
from  some  cause  the  lower  incisors  incline  inward,  thus 
causing  the  upper  ones  to  seem  more  protruding  than  they 
really  are. 


26 


ORTHODONTJA. 


FIG.   8. 


Mandibular  Protrusion. 


Lower  Protrusion  or  Prognathism. — This  deformity,  con- 
sisting in  the  abnormal  protrusion  of  the  lower  teeth  and 
jaw,  is  one  very  frequently  met  with.  In  some  cases  the 
lower  anterior  teeth  occlude  with  the  upper  ones,  but  pass 
outside  of  them,  while  in  others  the  lower  jaw  and  teeth  are 

protruded  to  such  an 
extent  as  to  make  the 
occlusion  of  the  lower 
anterior  and  side 
teeth  with  those  of  the 
upper  jaw  a  physical 
impossibility.  Fig.  8 
represents  an  ex- 
treme case  of  this 
character.  The  de- 
formity is  not  only 
very  unsightly,  but  interferes  seriously  with  mastication. 
No  doubt  it  is  due  in  many  cases  to  arrest  of  development 
of  the  upper  arch,  and  is  favored  by  any  cause  or  causes 
that  tend  to  lessen  the  extent  of  contact  in  occlusion.  That 
the  lower  jaw  possesses  an  inherent  tendency  to  move  for- 
ward when  occlusion  does  not  prevent  is  abundantly  shown 
in  cases  where  the  individual  has  become  edentulous  and 
no  artificial  teeth  are  worn.  Even  the  occlusion  of  artificial 
teeth  will  lessen  or  check  this  tendency. 

In  many  cases  it  is  an  undoubted  inheritance,  while  in 
others  it  may  be  brought  about  by  local  conditions.  It  is 
liable  to  occur  in  all  cases  where  it  is  not  prevented  by 
the  mechanical  influence  of  occlusion. 

Gothic  Arch. — The  angular  or  Gothic  arch  is  not  an  un- 
common one.  In  a  typical  arch  of  this  character,  the  teeth 
instead  of  forming  a  rounded  arch,  are  arranged  in  two 
slightly  curved  and  convergent  lines,  which  meet  at  an  angle 
where  the  central  incisorsjoin  each  other.  The  molars,  bicus- 
pids and  cuspids  are  usually  properly  related  to  one  another, 
but  simply  thrown  inward,  forming  nearly  straight  lines 


ETIOLOGY. 


27 


FIG.  9. 


Gothic  Arch. 


instead  of  positive  curves.  The  incisors,  however,  by  this 
contraction  of  the  space  are  not  only  thrown  forward, 
but  turned  upon  their 
axes  so  that  their  lingual 
surfaces  present  toward 
each  other.  Fig.  9  repre- 
sents this  form  of  irregular- 
ity. It  is  in  all  cases  con- 
fined to  the  maxilla.  The 
pressing  forward  of  the 
incisor  teeth  and  their  tor- 
sion often  gives  such  prom- 
inence to  the  lip  that  the 
teeth  remain  exposed  even 
when  the  jaws  are  closed. 
In  addition  tothisunsight- 
liness,  the  speech  is  often 

seriously  affected  by  the  free  and  uncontrolable  escape  of 
air  when  speech  is  attempted. 

The  causes  responsible  for  this  condition  are  probably 
shrouded  in  greater  obscurity  than  those  of  any  other  form 
of  irregularity. 

The  crowding  of  teeth  during  eruption,  delayed  eruption 
or  mal-occlusion,  some  of  which  are  evidently  responsible 
for  many  forms  of  irregularity,  cannot  be  called  to  account 
for  this  condition,  for  none  of  them  could  press  the  teeth  into 
such  symmetrically  straight  lines.  Mr.  Charles  Tomes  be- 
lieves that  it  is  brought  about  by  the  pressure  of  the  muscles 
of  the  cheeks  upon  the  sides  of  the  arch  while  sleeping  with 
the  mouth  open,  and  that  this  habit  is  due  to  enlargement 
of  the  tonsils,  which  prevents  full  breathing  through  the 
nose. 

The  pressure  of  the  cheeks  covering  so  large  a  surface 
would  be  just  the  kind  of  force  likely  to  produce  this  sym- 
metrical contraction  of  the  arch,  but  we  are  confronted  with 
the  fact  that  in  mouth-breathing  the  jaws  are  never  held 


28  ORTHODONTIA. 

far  apart,  and  also  that  the  masseter  and  buccinator  mus- 
cles, owing  to  their  points  of  insertion,  stand  clear  of  the 
teeth,  so  that  even  when  somewhat  flexed,  they  could  not 
possibly  produce  pressure  upon  these  organs. 

The  condition  is  nearly  always  associated  with  a  high  and 
narrow  vault,  and  it  may  be  possible  that  both  of  these  fea- 
tures have  been  brought  about  by  imperfect  development  of 

FIG.  10. 


Constricted  Arch. 


adjacent  parts,  especially  of  the  vomer,  which  stands  in  the 
relation  of  a  pillar  or  support  to  the  palate. 

Constricted  Arch. — This  deformity,  though  less  common 
than  the  preceding  one,  and  giving  less  external  evidence 
of  its  existence,  is  far  more  likely  to  favor  decay  on  account 
of  increased  surface  contact.  In  seeking  an  explanation  for 
its  existence,  it  is  well  to  remember  that  the  bicuspid  teeth 
(the  ones  most  usually  affected)  are  situated  immediately 
beneath  the  deciduous  molars,  and  succeed  to  their  positions. 
As  the  first  set  occupies  an  arch  in  every  way  smaller  than 


ETIOLOGY.  29 

the  permanent  one,  the  position  of  the  bicuspids  would 
locate  them  inside  of  the  arch  line  described  by  the  perma- 
nent teeth  already  in  place.  When  there  is  no  obstacle  to 
prevent,  they  naturally  move  outward  into  place ;  but  where 
insufficient  space  does  not  permit  this,  they  are  obliged  to 
remain  where  they  are,  or  in  an  effort  to  force  their  way  into 
line,  assume  a  crowded  and  irregular  position. 

The  fact  that  when  bicuspids  are  out  of  line  they  are 
nearly  always  found  to  be  in  lingual  malposition  seems  to 
favor  the  supposition  that  the  irregularity  has  been  brought 
about  in  the  manner  suggested.  Early  eruption  of  the 
cuspids  and  tardy  eruption  of  the  bicuspids  would  also 
favor  the  condition. 

The  assumption  that  bicuspids  once  in  line  may  be  forced 
out  of  it  by  pressure  exerted  in  the  eruption  of  the  second 
and  third  molars  has  little  to  support  it.  Were  this  possible 
or  probable  the  deformity  would  be  more  frequently  met 
with.  Fig.  10  is  a  fair  representation  of  this  deformity. 
Both  sides  of  the  arch  are  not  usually  affected  to  the  same 
extent,  and  in  some  cases  the  two  bicuspids  on  one  side 
occupy  a  position  directly  across  the  arch,  each  one  being 
partly  turned  upon  its  axis.  The  condition  is  rarely  met 
with  in  the  lower  jaw,  and  is  one,  according  to  the  author's 
observation,  never  inherited,  but  always  acquired. 


CHAPTER  III. 

FACIAL  HARMONY  AND  OCCLUSAL  RELATION. 


FACIAL  HARMONY. 

Facial  beauty  may  be  defined  as  the  harmonious  relation 
of  the  various  features  as  determined  by  the  standard  of  the 
observer. 

A  common  type  of  beauty  among  mankind  in  general 
would  probably  be  impossible  to  establish  since  each  race 
would  naturally  have  its  own  standard  by  comparison  with 
which  all  other  types  would  be  judged  unfavorably. 

The  features  of  a  typical  African  are  doubtless  more  har- 
monious and  beautiful  to  one  of  his  own  race  than  those  of 
a  Mongolian  or  Caucasian,  while  to  either  of  the  latter  the 
physiognomy  of  the  former  is  the  opposite  of  esthetic. 

Therefore  in  trying  to  determine  upon  a  type  of  facial 
beauty  for  our  guidance  we  will  have  to  confine  ourselves 
largely  to  our  own  race,  the  Anglo-Saxon,  or  perhaps  in  a 
broader  sense,  the  Caucasian. 

The  Greeks  established  a  type  of  beauty  the  elements  of 
which  were  found  among  their  own  people,  while  the  Romans 
had  another  originating  in  the  same  way. 

Each  of  these  is  shown  in  the  painting  and  sculpture  of 
their  respective  eras;  the  Greek  ideal  of  facial  harmony 
being  exemplified  in  the  well  known  statues  of  the  Apollo 
Belvidere  and  the  Hermes  of  Praxiteles. 

The  Anglo-Saxons  can  hardly  be  said  to  have  established 
a  type  of  their  own  and  they  incline  to  accept  the  Apollo 
type  as  more  nearly  representing  their  ideal  than  any  other. 

The  measurements  of  the  Apollo  profile  show  that  a  line 
drawn  from  the  frontal  eminence  to  the  most  prominent 

30 


FACIAL    HARMONY.  31 

point  of  the  chin  will  pass  through  the  middle  of  the  ala  of 
the  nose;  touch  the  edge  of  the  lower  lip  and  be  slightly 
back  of  the  most  prominent  part  of  the  upper  lip. 

Again,  if  this  vertical  line  be  bisected  at  certain  points  it 
will  be  seen  that  the  space  between  the  nasal  ala  and  the 
frontal  eminence  is  about  equal  to  the  distance  between  the 
former  point  and  the  base  of  the  mandible. 

If  this  last  portion  be  divided  into  thirds  a  line  defining 
the  upper  third  will  pass  where  the  lips  meet. 

While  these  facts  are  of  vital  interest  to  the  painter  or 
sculptor  in  the  outlining  of  an  ideal  face  they  are  of  value  to 
us  principally  in  giving  us  an  idea  of  proportion  and  ena- 
bling us  more  readily  to  detect  variations  from  a  commonly 
accepted  type. 

It  lies  within  the  domain  of  the  orthodontist,  more  than 
any  other  specialist,  even  the  surgeon,  to  change  the  relation 
of  the  features  and  bring  them  more  nearly  into  harmony 
with  one  another,  notwithstanding  the  fact  that  his  field  of 
operations  is  necessarily  limited  to  that  portion  of  the  face 
lying  below  the  nose. 

Even  with  this  limitation  the  possibilities  of  his  art  are 
so  great  that  he  is  often  able  to  transform  a  homely  face  into 
one  of  comparative  beauty  by  the  enlargement  or  reduction 
in  size  of  one  or  both  arches  either  laterally  or  antero-poste- 
riorly ;  the  opening  of  the  bite  in  cases  where  too  close  ap- 
proximation of  upper  and  lower  teeth  causes  an  over-fullness 
of  the  lips ;  a  shortening  of  the  bite  when  the  lips  do  not 
meet,  and  more  frequently  than  in  all  other  cases  combined 
the  overcoming  of  any  slight  deformity  caused  by  the  mal- 
position of  one  or  a  few  teeth  in  any  portion  of  the  arch. 

The  most  noticeable  (because  the  most  extensive)  changes 
in  facial  expression  are  those  brought  about  in  deep-lying 
tissues  by  means  of  mechanical  appliances  operating  upon 
the  teeth  or  mandible. 

The  separation  of  the  superior  maxillary  bones  along 
the  line  of  the  median  suture  through  the  agency  of  force 


32  ORTHODONTIA. 

applied  to  the  teeth  is  now  one  of  the  accepted  methods  of 
rapidly  enlarging  the  upper  arch  to  afford  accommodation 
for  malposed  teeth. 

In  like  manner  the  moving  of  the  entire  mandible  either 
anteriorly  or  posteriorly  a  slight  distance  in  order  to  increase 
or  lessen  the  prominence  of  the  chin  is  a  procedure  fre- 
quently resorted  to. 

Either  of  these  two  major  operations  can  only  be  success- 
ful when  performed  early  in  life,  that  is,  at  a  time  when  the 
osseous  tissues  of  the  skull  are  developing  and  before  consol- 
idation of  either  tissue  or  suture  has  been  completed.  How- 
ever, when  undertaken  at  the  opportune  period  they  are  not 
only  eminently  successful  but  result  in  such  altered  dimen- 
sions or  relations  of  the  features  as  often  to  entirely  change 
and  correspondingly  improve  the  appearance  of  the  indi- 
vidual. 

Our  conception  of  typical  facial  outline  and  harmony  can 
and  should  be  developed  by  a  careful  study  of  the  features 
of  those  we  meet  from  day  to  day  in  public  conveyances  or 
assemblies  where  there  is  usually  opportunity  to  notice  in 
detail  the  facial  characteristics  of  those  about  us. 

In  this  way,  more  than  any  other,  we  will  be  able  not  only 
to  develop  the  ability  quickly  to  detect  the  character  of  any 
inharmony  but  it  will  make  us  more  expert  in  forming  a 
correct  diagnosis  in  cases  that  present  for  treatment. 

OCCLUSAL  RELATION. 

Closely  associated  with  Facial  Harmony  is  Occlusal  Rela- 
tion, for  while  we  may  have  a  slight  lack  of  perfect  occlu- 
sion combined  with  a  fair  amount  of  harmonious  expression, 
it  may  be  laid  down  as  a  rule,  with  but  few  exceptions,  that 
normal  occlusion  is  necessary  to  a  perfect  symmetry  of  the 
features. 

As  we  could  not  lengthen  or  shorten  the  nose  of  an  indi- 
vidual or  deflect  it  to  either  side  without  destroying  the  sym- 


OCCLUSAL    RELATION.  33 

metry  and  expression  of  the  face,  so  any  alteration  of  the 
dental  arches  by  undue  enlargement,  contraction  or  distor- 
tion must,  according  to  its  extent,  interfere  with  the  har- 
mony which  the  features  would  otherwise  obtain. 

It  is  fair  to  infer  that  the  teeth  were  so  designed  in  num- 
ber, size  and  arrangement,  as,  with  the  assistance  of  the  lips 
and  cheeks,  to  form  a  feature  of  the  face  that  should  be  in 
perfect  harmony  with  other  features. 

This  being  the  case  we  cannot  but  be  impressed  with  the 
importance  of  preserving  the  full  complement  of  teeth  and 
of  having  them  arranged  according  to  nature's  design. 

Aside  from  the  part  which  the  teeth  play  in  the  produc- 
tion of  facial  harmony  their  full  number  and  proper  rela- 
tion is  important  in  the  matter  of  use  or  mastication,  for  in 
accordance  with  their  form  and  relation  we  can  only  obtain 
the  best  service  from  them  when  they  meet  or  occlude 
according  to  the  original  design. 

What  this  normal  arrangement  is  we  shall  now  have  to 
consider  under  the  title  of  Occlusion. 

Occlusion,  in  a  dental  sense,  means  a  closing  or  coming 
together  of  the  teeth  of  the  two  jaws  presumably  as  in  the 
case  of  a  hinge  joint.  The  term  articulation  has  a  broader 
signification  in  that  it  is  usually  used  to  denote  movement  in 
various  directions,  as  in  most  of  the  joints  of  the  human 
body. 

To  avoid  confusion  in  the  use  of  both  terms  it  has  been 
very  generally  decided  to  discard  the  term  articulation  and 
to  so  broaden  the  term  occlusion  as  to  embrace  the  relation 
of  the  teeth  not  only  in  a  state  of  rest  but  in  their  manner 
of  contact  during  any  movement  of  which  they  are  capable. 

Benocclusion,  or  normal  occlusion,  is  well  illustrated  by 
Fig.  11  which  represents  the  teeth  of  a  Caucasian  in  a  state 
of  contact  or  rest. 

Starting  with  the  upper  cuspid  it  will  be  noticed  that  it 
overlaps  and  is  in  contact  with  the  lower  cuspid  and  first 
bicuspid.  The  buccal  cusp  of  the  upper  first  bicuspid  over- 


34 


ORTHODONTIA. 


laps  and  occludes  with  the  lower  first  and  second  bicuspids. 
The  upper  second  bicuspid  in  like  manner  occludes  with  the 
lower  second  bicuspid  and  the  anterior  buccal  cusp  of  the 
lower  first  molar.  The  anterior  buccal  cusp  of  the  upper 
first  molar  fits  into  the  buccal  sulcus  between  the  anterior 
and  middle  cusps  of  lower  first  molar.  The  anterior 
buccal  cusp  of  the  upper  second  molar  rests  in  the  sulcus 
between  the  buccal  cusps  of  the  lower  second  molar  while 
the  anterior  buccal  cusp  of  the  upper  third  molar  lies  in  the 
buccal  sulcus  separating  the  cusps  of  the  lower  third  molar. 
The  lingual  cusps  of  the  upper  molars  and  bicuspids  are 

FIG.  11. 


Typical  Occlusion  (Cryer). 

received  into  the  longitudinal  groove  or  sulcus  which  sepa- 
rates the  buccal  from  the  lingual  cusps  in  the  lower  ones, 
while  the  lingual  cusps  of  the  lower  bicuspid  and  molar 
teeth  pass  slightly  beyond  the  corresponding  cusps  above 
into  the  oral  space. 


OCCLUSAL    RELATION.  35 

The  marvellous  wisdom  shown  in  this  arrangement  of  the 
teeth  which  bear  cusps  is  manifested  in  the  three  important 
purposes  which  it  subserves : 

1.  In  the  eruption  of  the  teeth  the  inclined  planes  of  the 
cusps  of  those  teeth  first  in  position  assist  in  guiding  their 
antagonists  into  place. 

2.  The  interlocking  of  the  cusps  serves  to  retain  the  teeth 
of  each  jaw  in  their  normal  positions. 

3.  The  interdigitation  makes   possible  the  most  perfect 
crushing,  tearing  and  grinding  of  the  food  brought  between 
them. 

As  to  the  anterior  teeth,  all  of  the  upper  ones  overlap  the 
lower  and  as  the  centrals  above  are  considerably  wider  than 
their  fellows  below  they  overlap  both  the  centrals  and  part 
of  the  laterals.  The  laterals  above  also  being  somewhat 
wider  than  their  opponents,  overlap  them  and  also  a  portion 
of  the  lower  cuspids. 

This  greater  width  of  the  four  upper  incisors  not  only 
increases  the  size  of  the  upper  arch  anteriorly,  enabling  the 
upper  teeth  to  overlap  the  lower  for  the  purpose  of  incising 
food,  but  it  also  places  the  upper  cuspids  in  such  position  as 
to  interlock  with  the  lower  and  make  possible  the  wonderful 
interdigitation  of  all  of  the  posterior  teeth. 

From  this  study  of  the  arrangement  and  occlusion  of  the 
teeth  it  will  be  seen  that  every  tooth  in  each  jaw  occludes 
with  two  in  the  opposite  one  with  the  exception  of  the  lower 
centrals  and  the  upper  third  molars  and  that  the  only  por- 
tion of  the  occluding  surfaces  of  any  of  the  teeth  that  can- 
not be  brought  into  use  in  the  various  movements  of  the 
mandible  is  the  distal  incline  of  the  posterior  buccal  cusp 
of  the  upper  third  molar. 

If  then,  each  tooth  has  its  appointed  place  to  occupy  and 
acts  and  is  reacted  upon  by  its  neighbors  and  its  antago- 
nists it  is  evident  that  we  can  only  have  perfect  occlusion 
and  perfect  service  when  they  are  thus  arranged. 

Mahcdusion  consist^  in  any  deviation  from  the  foregoing 


36  OBTHODONTJA. 

order  whether  in  a  greater  or  less  degree.  The  malposition 
of  even  a  single  tooth  in  one  jaw  will,  in  consequence  of  the 
normal  lateral  pressure,  change  the  position  of  most  or  all 
of  the  other  teeth  in  the  same  arch  and  these  in  turn  by 
virtue  of  their  changed  occluding  surfaces  will  operate  to 
disarrange  those  in  the  opposite  jaw. 

The  malposition  of  any  of  the  larger  teeth  will  usually 
cause  a  serious  disarrangement  of  all  of  the  others  but  the 
slight  malposition  of  one  of  the  smaller  ones,  as  for  instance 
a  moderate  rotation  of  one  of  the  lower  incisors,  will  usually 
cause  so  slight  a  disturbance  of  the  occlusion  as  to  result  in 
no  serious  harm. 

In  fact  it  is  extremely  doubtful  whether  the  elaborate 
operation  of  enlarging  the  entire  arch  for  the  sake  of  mak- 
ing a  slight  change  in  the  position  of  a  small  tooth  would 
be  justifiable. 

Perfect  occlusion  is,  of  course,  desirable  but  it  may  have 
to  be  obtained  at  too  great  a  cost. 

Less,  than  perfect,  but  nevertheless  good,  serviceable 
occlusion  is  what  we  will  often  have  to  be  satisfied  with. 


CHAPTER  IV. 

CONDITIONS  GOVERNING  CORRECTION. 

Through  the  advancement  made  in  recent  years  in  the 
multiplication  and  perfection  of  mechanical  appliances  and 
the  better  understanding  in  regard  to  tooth-movement  and 
tissue-changes,  scarcely  any  deformity  of  the  mouth  and  teeth 
is  beyond  mechanical  remedy. 

But,  as  what  is  possible  may  not  always  be  desirable,  it 
is  important  to  consider  certain  matters  which  may  and 
should  influence  us  in  many  cases  before  deciding  upon 
undertaking  the  correction  of  cases  of  irregularity. 

AGE. 

Patients  may  present  for  corrective  treatment  at  almost  any 
age,  although,  of  course,  most  of  them  come  to  us  in  early 
life.  Under  favoring  conditions  the  operation  may  be  begun 
and  carried  forward  successfully  through  a  wide  range  of 
years,  the  author  having  succeeded  in  one  case  as  late  as 
the  forty-fifth  year. 

While  possible  up  to  and  past  middle  life  progress  at  so 
late  a  period  will  necessarily  be  slow  on  account  of  the 
density  of  the  alveolar  tissues,  and,  fortunately  for  us,  few 
postpone  correction  for  so  long  a  time. 

The  proper  age  at  which  to  begin  treatment  is  just  as  soon 
as  the  irregularity  is  noticed  and  the  teeth  sufficiently 
erupted  to  enable  us  to  make  attachment  to  them. 

There  are  two  valid  reasons  for  this  : 

1.  The  tissues  are  then  less  fully  calcified  arid  yield  read- 
ily to  pressure. 

2.  By  correcting  any  malposition  at  once  a  greater  and 
more  extensive  deformity  is  prevented. 

37 


38 


ORTHODONTIA. 


FIG.   12. 


Any  of  the  permanent  teeth  may  erupt  outside  or  inside 
of  the  arch  line.  If  allowed  to  remain  in  such  position  for 
any  length  of  time,  the  space  intended  for  their  accommo- 
dation will  soon  be  partly  occupied  by  the  adjoining  teeth 
and  the  subsequent  correction  of  the  irregularity  rendered 
more  difficult.  A  central  or  lateral  incisor  often  erupts  so 
that  its  incisal  edge,  instead  of  being  in  line  with  the  curve 
of  the  arch,  forms  an  angle  with  it. 

This  torsion  may  be  associated  with  an  overlapping  of  the 
adjacent  tooth  as  shown  in  Fig.  12,  where  the  turned  tooth 

occupies  less  space  in 
the  line  of  the  arch 
than  it  should.  By  al- 
lowing this  condition 
to  remain,  when  the 
pressure  of  the  later 
erupting  teeth  begins 
to  be  felt,  these  teeth 
will  be  pressed  still 
closer  together  and  the 
irregularity  be  con- 
firmed. Subsequently, 
when  the  correction  of 

Torsion  With  Overlapping.  ^      conditi(m       ig      at_ 

tempted,  there  will  not  be  sufficient  room  to  accommodate 
the  tooth  in  its  wider  aspect  and  the  adjoining  teeth  will 
have  to  be  pressed  apart  or  the  arch  expanded  to  obtain 
the  necessary  room  ;  whereas,  if  the  tooth  had  been  turned 
in  its  socket  before  the  eruption  of  the  other  teeth  the  opera- 
tion would  have  been  a  much  simpler  one. 

Fig.  13.  represents  a  case  in  which,  through  the  unwise 
and  premature  extraction  of  the  deciduous  cuspids,  all  of  the 
upper  incisors  have  erupted  lingually  and  the  condition 
has  been  allowed  to  remain  until  the  permanent  cuspids 
were  badly  misplaced.  Had  correction  been  undertaken 


CONDITIONS    GOVERNING    CORRECTION. 


39 


early  and  the  incisors  been  brought  into  line  the  cuspids 
would  have  assumed  their  normal  positions  and  the  present 
more  serious  condition  been  prevented. 

Parents  should  be  encouraged  to  present  their  children 
for  dental  ex- 
amination at 
frequent  inter- 
vals during 
the  entire  per- 
iod of  first  den- 
tition. This  is 
not  only  for 
the  purpose  of 
watching  the 
eruption  of 
the  deciduous 
teeth  but  also 
to  keep  them 
free  from  the 
ravages  of  de- 
cay. 

The  premature  loss  of  any  one  of  the  deciduous  set  may 
be  but  the  paving  of  the  way  for  an  irregularity  in  the  per- 
manent set,  while  even  the  diminishing  of  the  size  of  a  crown 
by  extensive  caries  will  tend  toward  the  same  end  by  les- 
sening the  size  of  the  arch. 

It  will  therefore  be  apparent  that  no  deciduous  tooth 
should  be  prematurely  lost  if  at  all  possible  to  prevent  it 
and  that  in  any  loss  of  tooth  substance  through  caries  the 
part  affected  should  be  restored  to  its  original  outlines  by 
filling. 

Only  in  this  way  can  we  preserve  the  size  of  the  arches 
and  provide  for  their  normal  enlargement  under  the  stimu- 
lus of  pressure  of  the  erupting  permanent  teeth. 


Result  of  Premature  Extraction. 


40  ORTHODONT1A. 

HEALTH. 

While  advocating  early  interference  in  the  correction  of 
malposition  of  any  of  the  teeth  the  writer  would  not  be 
understood  as  advocating  it  in  the  face  of  contraindications. 

The  health  and  strength  of  the  patient  at  the  time  of  any 
proposed  operation  is  so  important  a  consideration  that  k 
dare  not  be  disregarded. 

Fortunately,  quite  early  in  life,  or  while  the  permanent 
teeth  are  in  course  of  eruption,  very  little  interference  is 
usually  required  to  correct  any  deviation  from  the  normal, 
and  it  is  only  in  cases  where  this  earlier  assistance  has  been 
neglected  and  a  more  or  less  complicated  condition  allowed 
to  result  that  any  extensive  treatment  is  called  for. 

Therefore  when  a  patient  has  reached  the  age  of  twelve 
or  fourteen  years  before  being  brought  to  us  for  treatment 
we  will  sometimes  find  it  necessary  to  decide  whether  the 
required  operations  shall  be  begun  at  once,  or  delayed  until 
later. 

This  is  the  period  when  important  changes  are  taking 
place  in  the  entire  economy.  The  individual  is  passing 
from  the  stage  of  childhood  into  that  of  manhood  or  woman- 
hood and  in  this  change,  especially  in  the  case  of  the  female, 
the  life-forces  are  taxed  to  the  utmost. 

It  is  also  the  time  when  the  mental  faculties  are  kept  at 
their  greatest  tension  in  school  work.  To  meet  these  condi- 
tions successfully  the  system  should  be  fully  sustained 
and  this  requires  not  only  nourishing  food  but  its  proper 
preparation  by  mastication. 

If  many  of  the  teeth  are  kept  tender  at  this  period  by 
extensive  movement  mastication  cannot  be  performed  prop- 
erly and  the  system  will  suffer  in  consequence. 

By  the  present-day  methods  of  regulating  great  tender- 
ness of  the  teeth  can  usually  be  prevented,  but  in  special 
cases  it  may  be  necessary  to  consider  the  advisability  of 
causing  even  great  discomfort. 


CONDITIONS    GOVERNING    CORRECTION.  41 

SEX. 

If  the  results  of  neglected  irregularity  are  deplorable  in 
regard  to  one  sex  they  are  certainly  so  in  regard  to  the  other, 
but  the  necessity  for  correction,  regarded  from  an  aesthetic 
point  of  view,  is  certainly  greater  in  woman. 

Facial  harmony  or  beauty  means  more  to  a  woman  than 
a  man  because  it  is  looked  upon  as  one  of  her  rightful  attri- 
butes, while  man,  if  any  deformity  in  the  lower  half  of  the 
face  exists,  has  a  means  of  concealing  it  which  woman  does  not 
possess.  But  in  the  attainment  of  facial  comeliness  through 
orthodontic  operations  it  must  not  be  forgotten  that  our 
patient  is  usually  a  maiden  or  a  child  who  at  that  period  of  life 
needs  tender  handling.  At  the  same  age  a  robust  boy  can 
undergo  an  operation  that  in  a  tender  girl  might  result  in 
nervous  shock  or  even  greater  physical  harm. 

For  this  reason,  if  in  the  course  of  our  operations  we  find 
that  the  young  patient  is  being  taxed  to  an  undue  extent, 
as  may  be  evidenced  by  nervous  irritability,  loss  of  appetite 
or  insomnia  it  is  advisable  and  indeed  imperative,  that  we 
temporarily  suspend  operations  until  a  normal  condition  is 
restored.  Conference  with  the  mother  will  aid  us  materially 
in  deciding  upon  what  is  best. 

A  loss  of  general  health  could  never  compensate  for  an 
improvement  of  the  dental  organs,  however  great. 


CHAPTER  V. 

EXTRACTION. 

The  question  of  extraction  in  its  relation  to  orthodontia  is 
one  of  such  serious  import  that  it  needs  to  be  approached 
and  discussed  without  partiality  or  prejudice. 

The  results  of  the  practice  are  so  far-reaching  that  we 
must  be  careful  not  to  err  in  deciding  whether  to  resort  to 
it  or  not  in  cases  that  come  to  us  for  treatment. 

It  would  be  unfair  and  possibly  misleading  to  say  that 
any  particular  line  of  practice  is  wholly  good  or  wholly  bad, 
or  that  it  should  always  be  practiced  or  never. 

Even  the  poorest  method  of  procedure  may  be  found  to 
contain  some  good  features  and  the  best  methods  some  objec- 
tionable ones. 

The  resort  to  extraction  in  the  treatment  of  cases  of  irreg- 
ularity was  at  one  time  quite  common,  but  careful  observa- 
tion of  the  results  has  caused  it  to  fall  more  and  more  into 
disfavor. 

In  some  instances  it  was  considered  necessary  in  order  to 
obtain  the  desired  improvement,  while  in  others  it  was 
looked  upon  as  the  best  means  of  simplifying  the  operation. 

Experience  has  taught  that  it  is  very  seldom  necessary, 
and  that  while  it  does  simplify  the  procedure  it  does  so 
usually  at  the  expense  of  other  valuable  desiderata. 

Again  it  has  been  argued  that  if  a  proposed  operation  is 
not  reduced  to  its  simplest  forms,  usually  by  extraction,  the 
patient  or  parent  in  some  cases  will  not  consent  to  having 
anything  done  and  that  the  patient  will  thus  not  be  benefited 
at  all.  This  argument  will  carry  some  weight  in  hospital  or 
infirmary  practice  and  also  in  certain  cases  among  the  worthy 
poor  but  the  instances  in  which  it  would  apply  are  so  few 
as  to  be  decidedly  exceptional. 

49 


EXTRACTION. 


43 


FIG.  14. 


Sometimes  a  presenting  case  of  irregularity  may  be  com- 
plicated by  the  presence  of  a  tooth  so  badly  decayed, 
broken  down  or  diseased  that  extraction  would  seem  justi- 
fiable if  not  absolutely  necessary,  but  even  in  such  case  if 
the  tooth  be  be- 
yond the  possi- 
bility of  being 
restored  to  use- 
fulness by  treat- 
ment, filling  or 
crowning  and 
the  roots  must 
be  extracted  we 
still  have  the 
means  of  reme- 
dying the  evil 
by  the  inser- 
tion of  a  small 
bridge  and  thus 
preserving  the 
space  and  re- 
storing the  oc- 
clusion. 

While,  as  a 
rule,  the  loss  of 
a  tooth  (without 
artificial  substi- 
tution) will  dis- 
turb the  posi- 
tion of  most  of 
the  other  teeth  in  the  arch  and  unfavorably  influence  those 
in  the  opposite  arch,  there  are  exceptional  cases  in  which 
the  ill-results  are  not  particularly  great. 

Fig.  14  illustrates  a  case  of  this  character  in  which  an 
upper  left  first  molar  was  extracted  to  make  room  for  the 
left  cuspid  which  had  erupted  in  labial  malposition. 


Loss  of  Molar  Without  Serious  Harm. 


44 


ORTHODONTIA. 


When   the   patient   came   into   the    author's   hands    no 
good  results  had  followed  the  extraction,  but  by  moving 
the  bicuspids  posteriorly  and  drawing  the  cuspid  into  posi- 
FIG.  15.  tion  the  irregular- 

ity was  corrected 
and  the  molar 
space  obliterated. 
Fig.  15  shows 
the  occlusion  on 
the  affected  side 
after  correction, 
and  while  the  oc- 
clusion  is  not 
really  normal  it  is 
entirely  servicea- 
ble and  satisfac- 
tory. 

Fig.  16  shows  a 
half  view  of  a  com- 
pleted  case  in 
which  the  upper 
laterals  had  been 
turned  upon  their 
axes  and  greatly 
overlapped  the 
centrals.  The  lower 
arch  being  normal 
in  outline  and  call- 
ing for  no  treat- 
ment the  first  bi- 
cuspids were  ex- 
tracted, the  cus- 
pids and  laterals 
moved  posteriorly 
and  the  latter  ro- 
tated. 

Extraction  of  First  Bicuspids  to  Correct  Overlapping 
of  Laterals. 


Satisfactory  Occlusion. 

FIG.  16. 


EXTRACTION.  45 

As  will  be  seen  the  resulting  occlusion  is  good,  though 
not  perfect,  while  the  formerly  protruding  lip  has  fallen 
back  into  place  and  the  facial  outline  is  perfectly  har- 
monious. 

FIG.  17. 


Nature  as  Orthodontist. 


Fig.  17  is  presented  as  a  unique  case  in  which  nature 
assumed  the  place  of  the  orthodontist,  producing  results  not 
anticipated. 

Some  twenty  years  ago  the  patient,  then  a  young  lady  of 
sixteen,  presented  for  the  correction  of  the  irregularity  shown 
in  figure  on  the  left.  The  first  molar  was  decayed  to  the 
roots  and  was  therefore  extracted. 

An  appliance  was  attached  to  the  second  molar  for  the 
purpose  of  first  drawing  backward  the  second  bicuspid  and 
afterward  the  first  bicuspid  to  make  room  for  the  out- 
standing cuspid.  As  the  appliance  caused  some  pain  the 
patient  removed  it  on  the  second  day  and  never  presented 
herself  until  two  years  later  when  the  teeth  were  found  to 
be  in  the  position  shown  in  figure  on  right.  The  second 
molar  had  moved  slightly  forward  while  the  cuspid  had 
forced  both  of  the  bicuspids  backward  and  had  assumed  its 
nearly  normal  place  in  the  arch. 


46  ORTHODONTIA. 

At  one  time  when  the  teeth  in  the  arch  were  crowded, 
especially  the  anterior  ones,  it  was  a  common  practice  to 
extract  one  or  both  first  molars  in  order  to  make  room. 
This  has  long  since  been  shown  to  be  faulty  practice, 
because  while  the  extraction  did  create  space  it  created  it  at 
a  point  too  far  removed  from  the  malposed  teeth  to  be  avail- 
able. After  the  anterior  teeth  were  moved  posteriorly  the 
molar  space  could  not  be  entirely  rilled  except  by  the  tip- 
ping forward  of  the  second  and  third  molars.  This  created 
a  serious  condition  of  malocclusion.  The  extraction  of  the 
second  bicuspid  was  a  little  less  objectionable  but  it  also  was 
too  far  removed  from  the  point  of  difficulty  to  avail  much. 

The  extraction  of  any  of  the  anterior  teeth  being  out  of 
the  question  the  matter  of  extraction  in  any  case  where  it 
may  seem  to  be  advisable  or  called  for,  resolves  itself  into 
one  of  extraction  of  the  first  bicuspids. 

If,  therefore,  these  are  the  only  teeth  that  it  might  ever  be 
considered  good  practice  to  extract  we  may  conclude  that 
their  loss  would  only  be  justifiable; — 

1.  Where  both  the  upper  and  lower  teeth  on  one  side  of 
the  arch  are  in  normal  position  and  occlusion,  while  on  the 
other  side  a  central,  lateral  or  cuspid  has  erupted  labially 
with  no  space  in  the  arch  for  its  accommodation. 

In  such  case  if  the  overbite  be  normal  and  the  bicuspids 
and  molars  on  the  affected  side  are  in  nearly  normal  occlusion 
the  extraction  of  the  first  bicuspid  would  seem  to  be  a  better 
procedure  than  the  enlargement  of  the  entire  arch  without 
resort  to  extraction. 

2.  Where  the  harmony  of  the  features  is  only  marred  by 
the  malposition  of  the  cuspids  and  where  the  enlargement 
of  the  anterior  portion  of  the  arch  to  create  space  for  them 
would  result  in  a  decided  and  unnatural  protrusion. 

3.  Where  the  irregularity  pertains  to  both  the  upper  and 
lower  anterior  teeth  alone,  with  the  side  and  posterior  teeth 
in  good  occlusion  and  where  the  alignment   of  upper  and 
lower  anterior  teeth  would  create  an  unsightly  protrusion. 


EXTRACTION.  47 

Cases  of  this  character  are  exceedingly  rare  but  when  met 
with  the  extraction  of  all  four  first  bicuspids  is  indicated. 

But,  while  extraction  may  be  advisable  in  a  few  cases 
there  are  many  reasons  why  it  should  not  be  resorted  to 
hastily  or  unadvisedly. 

y  1.  Extraction  of  even  a  single  tooth  before  all  of  the  teeth 
in  the  arch  are  fully  erupted  and  in  place  necessarily  lessens 
the  size  of  the  arch.  It  does  this  by  the  lack  of  that  stimu- 
lative pressure  which  accompanies  the  later  eruption  of  the 
posterior  teeth,  so  that  with  one  arch  lessened  in  size  and 
the  other  of  normal  amplitude  malocclusion  will  be  una- 
voidable. 

2.  Disarrangement  of  occlusion,  if  it  be  at  all  extensive, 
will  in  nearly  all  cases  result  in  shortening  the  bite  which 
will  be  followed  by  undue  wearing  of  the  upper  incisors  and 
frequently  also  by  their  separation. 

3.  Tipping   of    teeth,   especially   in    the    molar   region. 
This,  as  stated,  causes  serious  malocclusion  with  lessened 
masticating  surface  and  greater  liability  to  proximate  decay. 
Also,  when  the  tipping  tooth  is  a  lower  molar  the  two  pos- 
terior cusps  (the  ones  in  occlusion)  will  serve  as  a  wedge  to 
drive  the  opposing  upper  molars  apart  producing  a  perma- 
nent space  for  the  lodgment  of  food  and  disarranging  the 
occlusion  as  well. 

4.  After  an  operation  for  correction,  if  any  interdental 
space  exist,  caused  by  extraction,  it  will  be  virtually  impos- 
sible to  hold  the  teeth  in  their  new  positions  because  of  the 
opportunity  offered  for  teeth  to  move  toward  the  space. 

The  normal  interdigitation  of  cusps  has  proven  to  be  one 
of  the  best  retainers,  often  taking  the  place  of  a  retaining 
appliance  and  in  cases  where  the  latter  must  be  worn  normal 
occlusion  will  so  aid  the  operation  of  retention  as  to  mate- 
rially lessen  the  time  in  which  the  teeth  will  grow  firm. 

In  the  balancing  of  these  reasons  for  and  against  extrac- 
tion as  a  rule  of  practice  it  must  be  very  apparent  that  the 
latter  greatly  outweigh  the  former.  If  further  evidence  on 


48  ORTHODONTIA. 

this  point  were  needed  it  could  be  found  in  the  many  cases 
presenting  for  treatment,  in  which,  as  a  consequence  of 
extraction,  almost  hopeless  deformity  of  the  dental  organs 
has  resulted. 

In  some  cases  of  this  character  our  skill  will  be  able  to 
bring  about  some  improvement,  but  it  will  not  be  as  great 
nor  as  easily  accomplished  as  though  extraction  had  not 
been  resorted  to. 

In  view,  therefore,  of  the  difficulty  of  correcting  an  error 
made  by  the  removal  of  a  tooth  when  it  should  have  been 
retained  it  ma}T  be  well  to  lay  down  the  following  rules  for 
the  guidance  of  the  inexperienced. 

1.  Do  not  decide  to  extract  until  a  careful  study  and 
restudy  of  the  case  has  been  made  from  articulated  models 
and  the  patient  in  person,  and  until  every  available  method 
of  procedure  without  extraction  has  been  carefully  consid- 
ered. 

2.  If  extraction  seems  unavoidable,  adopt  the  best  method 
of  correction  without  it  and  when  in  the  course  of  the  opera- 
tion it  becomes  absolutely  evident  that  the  desired  result 
cannot  be  obtained  in  that  way  it  will  still  be  time  to  extract 
and  change  our  method  of  procedure. 

As  long  as  it  will  be  necessary  to  amputate  any  member 
or  organ  of  the  human  body  in  order  to  preserve  the  life 
or  well  being  of  an  individual,  so  long  may  it  be  necessary 
to  remove  a  tooth  or  two  for  the  same  reasons. 

In  dentistry,  however,  as  in  surgery,  the  operation  should 
be  one  of  last  resort. 


CHAPTER  VI. 

PHYSIOLOGY  OF  TOOTH-MOVEMENT  AND  CHARACTER  OF 
TISSUES  INVOLVED. 

In  changing  the  position  of  teeth  in  the  act  of  regulating, 
the  surrounding  tissues,  both  hard  and  soft,  are  largely 
involved. 

In  order,  therefore,  to  properly  comprehend  the  philosophy 
of  tooth  movement,  it  is  necessary  to  understand  the  struc- 
tural character  of  these  tissues  and  the  physiological  changes 
that  take  place  in  them  while  a  tooth  is  being  moved,  and 
afterward. 

The  Alveolar  Process. — This  process,  as  its  name  implies, 
is  not  a  separate  and  distinct  bone,  but  a  provisional  struc- 
ture designed  to  support  the  teeth  in  position  and  afford 
lodgment  for  the  nutrient  vessels  leading  to  them.  It  is 
formed  upon  the  body  of  the  bones  of  the  jaw  as  the  teeth 
are  developed,  growing  with  them  until  they  are  fully 
formed,  and  then  remaining  while  they  remain. 

When  the  teeth  are  lost,  there  being  no  longer  any  special 
use  for  it,  most  of  this  process  is  resorbed  and  carried  away. 
In  early  infancy  little  alveolar  structure  exists,  but  it  is 
formed  co-ordinately  with  the  growth  of  the  deciduous  teeth 
and  remains  during  the  period  of  their  retention.  Should 
they  be  lost  before  their  successors  are  ready  to  appear,  the 
process  will  be  entirely  removed  by  resorption,  and  a  new 
one  formed  for  the  accommodation  of  the  permanent  teeth. 
Where,  however,  the  deciduous  teeth  are  gradually  shed  to 
make  way  for  their  successors,  the  process  is  not  entirely 
resorbed,  the  basal  and  unabsorbed  portion  serving  as  a 
foundation  upon  which  the  new  structure  is  formed. 

The  alveolar  process,  being  built  or  formed  upon  the  body 
of  the  maxillary  bones,  conforms  to  them  in  outline  and 

49 


50  ORTHODONTIA. 

describes  the  same  curves.  In  depth  it  corresponds  to  the 
length  of  the  roots  of  the  teeth,  while  in  width  it  is  sufficient 
to  envelop  all  of  that  portion  of  the  tooth  beyond  the  termi- 
nation of  the  enamel.  It  gradually  increases  in  thickness 
as  it  approaches  the  body  of  the  bone  upon  which  it  re^ts. 

It  consists  of  an  outer  and  inner  plate  united  at  intervals 
by  septa,  thus  forming  alveoli  for  the  accommodaiion  of 
the  roots  of  the  teeth.  Its  main  portion  is  not  compact,  but 
open  and  spongy,  resembling  the  cancellate  structure  of  the 
diploe  of  the  bones  of  the  cranium  and  the  inner  portion  of 
other  bones.  Its  outer  or  cortical  layer  is  very  dense  and 
hard,  and  therefore  offers  gj'eater  resistance  to  the  moving 
of  a  tooth,  than  the  more  open  structure  beneath.  Its  cellu- 
lar structure,  while  giving  it  sufficient  firmness  to  assist  in 
supporting  the  teeth  in  their  positions,  affords  opportunity 
for  the  lodgment  and  passage  of  the  vessels  of  nutrition  and 
sensation  with  which  it  is  so  bountifully  supplied. 

Owing  to  its  peculiar  structure  and  great  vascularity,  the 
alveolar  process  is  readily  resorbed  under  the  stimulus  of 
pressure,  and  as  readily  reproduced  behind  the  moving  teeth. 

The  Teeth. — Of  the  teeth  themselves  little  need  be  said. 
The  student  is  familiar  with  their  number,  shape,  position 
and  structure.  Being  the  most  compact  organs  of  the 
human  body,  the  application  of  any  force  necessary  to  their 
movement  will  not  injuriously  affect  them  so  far  as  their 
hard  tissues  are  concerned. 

The  ease  or  difficulty  with  which  they  may  be  made  to 
change  their  positions  is  dependent  upon  the  number  and 
length  of  their  roots  and  the  thickness  of  the  process  sur- 
rounding them.  All  of  the  upper  teeth  can  be  more  readily 
moved  outward  than  inward,  on  account  of  the  thin- 
ness of  the  external  alveolar  plate.  The  ten  single-rooted 
teeth  in  the  lower  jaw  may  be  moved  outward  or  inward 
with  equal  ease,  while  the  lower  molars  are  more  readily 
moved  inward. 

All  of  the  teeth  can  be  more  easily  moved  in  the  line  of 


PHYSIOLOGY.  51 

the  alveolar  arch  than  outward  or  inward,  because  the  septa 
are  composed  entirely  of  cancellate  tissue  which  yields 
readily  to  pressure  and  is  quickly  resorbed. 

The  Pulp. — The  pulp  is  the  formative  organ  of  the  dentin 
and  after  calcification  is  complete  it  remains  as  the  princi- 
pal source  of  nutrient  supply  for  that  tissue.  It  is  com- 
posed of  fibrous  connective  tissue,  with  numerous  nerve 
filaments  which  enter  through  or  near  the  apical  foramen. 
Ramifications  of  minute  blood-vessels  are  noticeable  through- 
out its  whole  extent,  giving  color  to  the  organ  and  consti- 
tuting its  vascular  system. 

It  bears  an  important  relation  to  the  teeth  in  their  move- 
ment, since  it  may  be  readily  devitalized  through  impru- 
dence or  lack  of  care.  Before  calcification  of  the  teeth  has 
been  completed  the  apical  foramen  is  large  and  easily  accom- 
modates the  pulp  where  it  enters  the  tooth.  After  calcifica- 
tion is  complete  the  apical  foramen  is  small  and  the  pulp 
at  this  point  is  in  consequence  greatly  reduced  in  size.  In 
the  ordinary  movement  of  teeth  there  is  generally  a  mechani- 
cal constriction  of  the  pulp  at  the  apex  due  to  the  tipping  of 
the  tooth  in  moving.  If  the  movement  be  rapid  in  teeth 
fully  calcified  (after  the  sixteenth  or  eighteenth  year)  this 
constriction  may  be  so  great  as  to  cause  death  of  the  pulp 
through  strangulation.  Before  complete  calcification  this  is 
not  likely  to  occur,  from  the  fact  that  when  the  foramen  is 
large  the  pulp  has  more  space  for  its  accommodation. 

In  the  movement  of  a  tooth  in  the  direction  of  its  length 
the  pulp  may  become  devitalized  through  excessive  stretch- 
ing. This  has  occurred  at  times  in  drawing  down  into 
line  a  tooth  that  has  been  retarded  in  eruption.  In  all 
such  cases  care  must  be  exercised  and  the  movement  con- 
ducted slowly. 

The  Pericementum. — The  pericementum  or  peridental 
membrane  is  that  tissue  which  envelops  the  root  of  the  tooth 
and  fills  the  space  intervening  between  it  and  the  alveolar 
wall.  It  is  a  tough,  strong  membrane,  composed  mainly  of 


52  ORTHODONTIA. 

fibrous  connective  tissue,  permeated  with  blood-vessels  and 
nerve  fibres  and  containing  traces  of  a  lymphatic  system. 

It  is  strongly  adherent  to  the  alveolar  wall  of  the  socket 
on  the  one  hand,  and  to  the  cementum  of  the  tooth  on  the 
other,  its  adherence  being  due  to  the  extension  of  its  fibres 
into  both  the  bone  and  the  cementum.  These  fibres,  accord- 
ing to  Prof.  Black,*  "  are  wholly  of  the  white  or  inelastic 
connective  tissue  variety,"  and  the  apparent  elasticity  of  the 
membrane  is  due  to  the  passage  of  most  of  the  fibres  from 
cementum  to  wall  in  an  oblique  direction,  in  such  a  way  as 
to  "swing  the  tooth  in  its  socket." 

This  membrane  is  the  formative  organ  of  the  cementum 
of  the  tooth,  and  also  assists  in  building  the  walls  of  the 
alveoli. 

The  cells  concerned  in  the  building  of  the  bony  walls  are 
known  as  osteoblasts,  and  those  forming  the  cementum  are 
designated  cementoblasts.  After  these  cells  have  performed 
their  normal  function,  some  of  them  become  encapsuled  and 
form  part  of  the  tissue  they  were  instrumental  in  building. 

When  re-formation  of  tissue  is  demanded,  as  in  the  thick- 
ening of  the  alveolar  wall,  or  in  increasing  the  normal 
amount  of  cementum  at  various  points  under  certain  con- 
ditions, cells  upon  the  surface  are  excited  into  activity  and 
perform  the  work.  In  the  moving  of  a  tooth  the  activity  of 
these  new  cells  is  at  once  manifested  in  the  formation  of 
alveolar  tissue  to  fill  the  space  caused  by  the  advancing  tooth. 

Beside  these  cells  of  construction  and  repair,  the  perice- 
mentum  also  contains  cells  that  might  well  be  called  cells  of 
destruction.  They  are  the  osteoclasts  or  cementoclasts,  and 
their  function  is  to  break  down  or  resorb  the  cemental  or 
osseous  tissues  when  such  action  is  called  for. 

In  the' correction  of  irregularities  these  cells  perform  val- 
uable service  in  removing  bony  tissue  on  the  advancing 
side  of  the  moving  tooth. 

The  pericementum  is  thickest  in  childhood,  when    the 

*  Dental  Review,  vol.  I.,  p.  240. 


PHYSIOLOGY.  53 

sockets  or  alveoli  are  of  necessity  considerably  larger  than 
the  roots  of  the  teeth  which  they  contain.  With  advancing 
age  both  cementum  and  the  alveolar  walls  are  increased  in 
thickness  by  slow  but  continuous  growth  until  the  perice- 
mentum  is  greatly  reduced  in  thickness,  and  in  consequence 
the  diameter  of  the  roots  more  nearly  approximates  that  of 
the  alveoli  or  sockets. 

•The  pericementum  possesses  a  variet\r  of  function  not 
often  met  with  in  any  single  tissue  of  the  human  system. 

It  retains  the  tooth  in  its  socket  and  acts  as  a  cushion  to 
prevent  injury  to  the  adjoining  bony  structures  from  hard 
and  violent  concussions  to  which  the  teeth  are  sometimes 
subjected. 

It  affords  accommodation  for  numerous  blood-vessels 
which  supply  both  the  teeth  and  alveolar  tissue  with  nutri- 
ent material,  and  for  the  branches  of  nerves  which  consti- 
tute it  the  sensory  organ  of  the  tooth,  so  far  as  tactual 
impress  is  concerned. 

It  is  the  organ  of  construction  and  repair  of  both  cemen- 
tum and  bone,  and  is  also,  on  occasion,  the  organ  of  destruc- 
tion of  either  or  both  of  these  tissues. 

Physiology  of  Tooth  Movement. — In  the  ordinary  movement 
of  teeth  one  or  both  of  two  changes  take  place.  One  is  the 
resorption  of  alveolar  tissue  on  the  advancing  side  of  the 
tooth  and  its  re-formation  on  the  opposite  side,  and  the  other 
a  bending  of  the  alveolar  plate  in  the  direction  of  the  applied 
force.  The  cancel  late  tissue  is  easily  compressed  and  resorbed 
in  response  to  pressure,  but  the  cortical  layer  of  the  process 
offers  greater  resistance  and  is  less  readily  resorbed  on 
account  of  its  density. 

Where  the  cortical  layer  is  very  thin  at  the  alveolar 
border  as  on  the  labial  side  of  the  upper  anterior  teeth, 
and  on  both  the  labial  and  lingual  sides  of  the  lower  ante- 
rior teeth,  it  is,  of  course,  more  easily  bent  than  in  the  region 
of  the  posterior  teeth  where  it  is  thicker.  For  this  reason 
the  upper  anterior  teeth  yield  most  readily  to  force  applied 


54  ORTHODONTIA. 

in  an  outward  direction,  while  the  anterior  teeth  of  the 
lower  jaw  yield  almost  equally  to  a  force  directed  either 
labially  or  lingually. 

When  force  is  exerted  upon  a  single  tooth  for  the  purpose 
of  moving  it,  the  first  effect  produced  is  the  compression  of 
the  pericementum  between  the  tooth  and  aveolar  wall  on 
the  advancing  side,  and  the  stretching  of  the  same  membrane 
on  the  opposite  side.  In  the  compression  of  the  membrane 
the  blood  supply  is  partly  cut  off,  and  the  nerves,  by 
their  irritation,  create  a  sensation  of  pain  which  is  soon 
obliterated  by  the  semi-paralysis  brought  about  by  continued 
pressure.  At  the  same  time  this  irritation  stimulates  and 
hastens  the  development  of  the  osteoclasts  which  at  once 
begin  the  work  of  breaking  down  and  resorbing  that  por- 
tion of  the  socket  pressed  upon. 

Bony  tissue  being  thus  removed,  accommodation  is  made 
for  the  advancement  of  the  tooth  which  at  once  takes  place. 
Under  continued  pressure  this  action  is  renewed  again  and 
again  until  the  tooth  has  reached  its  intended  position. 
While  this  is  taking  place  on  the  advancing  side,  quite  an 
opposite  condition  prevails  on  the  side  from  which  advance- 
ment has  taken  place.  There  the  fibrous  tissue  of  the  peri- 
cementum has  been  subjected  to  extreme  tension,  greater 
room  has  been  -provided  for  the  accommodation  of  the 
nutrient  vessels,  and  osteoblasts  have  been  developed  for 
the  formation  of  bony  material  to  add  to  the  alveolar  wall 
and  thus  close  the  space  caused  by  the  movement  of  the 
tooth.  While  these  processes  of  resorption  and  reproduc- 
tion on  opposite  sides  of  the  tooth  have  been  going  on  coin- 
cidently,  their  results  have  been  very  unequal,  for  the 
resorption  of  bone  is  a  far  more  rapid  process  than  its 
formation. 

During  the  entire  time  of  moving,  and  for  a  long  time 
afterward,  the  tension  of  the  pericementum  on  the  free  side 
of  the  tooth  and  the  resiliency  of  the  bent  alveolar  plate  on 
the  advancing  side  are  kept  up  to  such  an  extent,  that  were 


PHYSIOLOGY.  55 

the  pressure  or  means  of  retention  removed,  the  tooth  would 
quickly  be  forced  back  into  the  space  created  by  its 
movement. 

The  tendency  on  the  part  of  the  tooth  to  return  to  its 
original  position  is  only  finally  overcome  when  the  deposit 
of  osseous  matter  in  the  alveolar  socket  is  sufficiently  great 
and  dense  to  resist  the  opposing  forces. 

While  this  process  of  reparative  construction  has  been 
going  on  the  tissues  about  the  opposite  side  of  the  tooth 
have  been  adjusting  themselves  to  the  new  condition.  The 
pressure  upon  the  tooth  having  ceased  no  more  bone  is 
resorbed  or  bent ;  any  injury  inflicted  upon  the  pericemen- 
tum  by  its  long  compression  is  repaired ;  the  nerves  and 
blood-vessels  resume  their  normal  functions,  and  the  tooth 
in  its  new  position  becomes  a  far  more  useful  member  of  the 
dental  organism  than  it  had  been. 

*"When  a  number  of  adjacent  teeth  are  moved  outward  in 
the  anterior  expansion  of  the  arch,  the  principal  change  that 
occurs  in  the  alveolar  process  is  a  distinct  bending  or  yield- 
ing of  the  entire  outer  plate.  This  is  evidenced  by  the 
rapidity  with  which  the  movement  takes  place,  and  also  by 
the  fact  that  after  the  movement  is  completed  the  process  is 
not  perceptibly  thinner  on  the  labial  side  or  thicker  on 
the  lingual  side  of  the  teeth  than  it  was  before  the  change 
took  place.  This  flexibility  ot  the  process  is  due  to  its 
incomplete  calcification  at  the  period  of  life  when  opera- 
tions for  irregularity  are  usually  undertaken.  That  the  one 
alveolar  plate  should  yield  to  pressure  is  more  readily  com- 
prehended than  that  the  opposite  one  should  follow,  but  the 
uniting  septa  being  strong  and  elastic  draw  the  one  plate 
after  the  other  as  the  movement  takes  place. 

In  lateral  expansion  of  the  arch,  especially  in  the  molar 
region,  it  is  more  than  probable  that  the  space  is  gained  by 
the  opening  of  the  median  suture  which  can  readily  occur 
early  in  life.  Frequently  the  arch  is  widened  a  quarter  of 
an  inch  or  more  with  little  effort,  and  this  could  hardly  be 


56  OBTHODONTIA. 

accomplished  by  the  bending  or  resorption  of  the  thick 
outer  cortical  layer  of  the  process  in  this  region.  A  separ- 
ation at  the  rear  of  the  hard  palate  would  not  likely  be 
attended  by  separation  anteriorly,  but  the  anterior  portion 
can  be  and  often  is  advantageously  separated  by  pressure 
in  cases  where  space  is  needed  for  the  accommodation  of 
crowded  incisors.  Separation  of  this  character  when  brought 
about  slowly  is  not  attended  by  any  pathological  symp- 
toms, but  it  should  only  be  attempted  after  the  permanent 
cuspids  are  fully  erupted,  and  before  the  walls  of  the  suture 
have  become  thoroughly  united. 

The  readiness  with  which  the  alveolar  process  yields  to 
pressure  early  in  life  is  an  important  aid  in  the  movement 
of  teeth  in  that  it  assists  in  hastening  and  simplifying  the 
operation,  but  advantage  should  not  be  taken  of  it  to  move 
teeth  too  rapidly  for  fear  of  endangering  the  vitality  of  the 
pulp. 

In  extrusion  (forcing  a  tooth  partly  out  of  its  socket)  the 
fibres  of  the  pericementum  are  stretched,  but  the  alveolar 
walls  do  not  undergo  any  material  change,  while  the  space 
created  about  the  apex  of  the  root  and  somewhat  along  its 
sides,  is  soon  filled  with  new  alveolar  tissue.  The  stretching 
of  the  nerve  and  blood-vessels  that  enter  the  apical  foramen 
will  not  be  injured  if  the  movement  be  conducted  slowly. 

In  intrusion  (forcing  a  tooth  farther  into  its  socket)  resorp- 
tion of  alveolar  tissue  about  the  root  takes  place  as  in  other 
cases,  and  the  nutrient  vessels  are  more  or  less  compressed, 
but  they  adjust  themselves  to  the  condition  without  any 
ill-results. 

Tissue  Changes  Subsequent  to  Tooth  Movement. — While  the 
foregoing  changes  take  place  during  the  movement  of 
teeth  and  their  subsequent  retention  there  are  others  occur- 
ring later  that  are  of  equal  importance. 

Every  one  who  has  had  large  experience  in  the  practice 
of  orthodontia  has  noticed  the  changes  in  the  way  of  im- 
provement that  have  taken  place  after  regulating  efforts 


PHYSIOLOGY.  57 

have  ceased,  and  usually  after  the  period  of  retention  has 
passed.  Immediately  after  moving  the  crowns  of  teeth  into 
normal  position  and  occlusion,  there  is  frequently  noticed  a 
lack  of  fulness  or  an  overfulness  about  the  roots  of  the  teeth 
that  have  been  moved  that  is  inharmonious.  The  necessary 
operations  have  been  performed,  the  teeth  are  arranged  as 
nature  intended  them  to  be,  normal  occlusion  has  been 
established  and  except  for  the  period  of  retention  the  case 
is  regarded  as  completed.  Still  there  exists  a  slight  lack  of 
harmony,  apparent  to  both  parent  and  operator,  which  is 
somewhat  disappointing.  The  same  case,  seen  a  few  months 
or  a  year  later,  will  show  marked  evidences  of  improvement 
which  could  not  well  have  been  anticipated  but  which  are 
as  gratifying  as  they  are  surprising. 

What  has  taken  place  is  nothing  more  than  the  result  of 
an  effort  on  the  part  of  nature  to  bring  about  normal  con- 
ditions. 

When  the  teeth  were  in  malposition  the  stimulus  of 
lateral  pressure  could  not  properly  assert  itself,  and  the 
alveolar  tissues  only  developed  sufficiently  to  support  the 
teeth  in  their  irregular  positions. 

After  rearrangement  of  the  crowns,  and  the  coincident 
pressure  upon  the  roots,  nature  again  exerted  herself  to  build 
up  or  resorb  tissue  in  order  to  establish  relations  in  con- 
sonance with  her  original  design.  This  change  is  neces- 
sarily a  slow  one,  and  hence  its  results  become  apparent 
much  later  than  we  should  prefer. 

In  the  correction  of  any  extensive  or  marked  cases  of  irreg- 
ularity this  subsequent  or  post-operative  improvement 
should  be  taken  into  account,  and  will  probably  be  most 
evident  where,  through  the  labial  movement  of  the  crowns 
of  the  upper  incisors  and  cuspids,  a  lack  of  fulness  is 
noticeable  over  their  roots,  and  especially  at  their  apices. 

Nature  may  not  restore  all  of  the  desired  fulness,  but 
she  will  usually  accomplish  much  toward  that  end. 


CHAPTER  VII. 

DYNAMICS  OF  TOOTH  MOVEMENT. 

The  use  of  force  in  overcoming  resistance  and  causing 
malposed  teeth  to  assume  their  proper  positions  falls  within 
the  domain  of  that  branch  of  Physics  known  as  Dynamics. 

The  movement  of  teeth,  like  the  movement  of  other 
bodies,  is  regulated  and  controlled  by  certain  general  prin- 
ciples or  laws,  and  a  proper  understanding  of  such  of  them 
as  are  of  importance  to  us  in  our  work  is  necessary  in  order 
that  the  required  operations  may  be  performed  intelligently 
and  in  a  scientific  manner. 

To  construct  a  machine  which  by  its  action  will  accom- 
plish a  desired  result  may  be  easy,  but  to  devise  one  which 
will  give  us  the  best  result  without  a  waste  of  energy  or  an 
opposing  ill-result,  requires  familiarity  with  the  principles 
upon  which  it  is  to  operate  and  the  attendant  conditions 
which  may  limit  or  control  its  action. 

Three  mechanical  factors  enter  into  the  problem  of  tooth 
movement. 

1.  Secure  anchorage. 

2.  Proper  application  of  force. 

3.  Character  of  resistance  to  be  overcome. 

Secure  Anchorage. — One  of  the  three  laws  governing  the 
application  of  force  as  enunciated  by  Newton  is: — Reaction 
is  always  equal  and  opposite  to  action.  A  jackscrew,  for 
instance,  placed  under  a  house  to  elevate  it  exerts  as  much 
pressure  upon  the  ground  as  it  does  upon  the  building,  but 
as  the  resistance  of  the  ground  or  foundation  is  much 
greater  than  that  offered  by  the  house,  the  latter  rises  when 
the  screw  is  turned.  If  the  same  jackscrew  were  placed 
horizontally  between  two  piles  of  equal  size  implanted  in 
the  earth  to  the  same  depth,  each  would  move  equally  when 
the  screw  was  turned,  because  one  offered  no  more  resist- 
ance than  the  other,  action  and  reaction  being  always  equal. 

58 


DYNAMICS    OF    TOOTH    MOVEMENT.  59 

In  like  manner  a  screw  operating  between  two  similar  teeth, 
as  molar  and  molar  or  cuspid  and  cuspid,  would  under 
similar  conditions  move  one  as  much  as  the  other.  When, 
therefore,  it  is  desired  to  move  but  one  of  the  teeth  between 
which  the  appliance  operates  the  one  used  as  an  anchorage 
must  be  much  more  firmly  implanted  than  the  one  to  be 
moved.  A  cuspid  would  not  serve  as  anchorage  in  moving 
another  cuspid  nor  a  molar  for  a  molar,  but  either  a  molar 
or  a  cuspid  might  offer  sufficient  resistance  for  the  moving 
of  a  tooth  of  less  fixedness,  like  an  incisor  or  a  bicuspid. 
Even  in  such  case,  however,  a  single  anchor  tooth  as  firmly 
implanted  as  a  multi-rooted  molar  or  a  long-rooted  cuspid 
would  be  likely  to  be  moved  somewhat  out  of  position. 

To  secure  as  stable  anchorage  as  possible,  therefore,  we 
must  resort  to  one  of  the  following  methods : 

1.  Combine  the  resistance  of  several  teeth. 

2.  Counterbalance  the  force  exerted  upon  the  anchor  tooth 
or  teeth  in  one  direction  by  another  force  in  the  opposite 
direction,  thus  making  the  forces  reciprocal. 

3.  Use  the  teeth  in  one  jaw  to  resist  the  force  applied  to 
move  teeth  in  the  opposite  jaw.     Intermaxillary. 

4.  Obtain  anchorage  or  resistance  at  some  point  outside 
of  the  mouth,  as  on  the  top  or  back  of  the  head. 

In  any  proposed  movement  of  a  single  tooth,  either  for- 
ward or  backward  in  the  line  of  the  arch,  it  has  long  been 
customary  to  select  as  an  anchor  tooth  one  having  others 
adjoining  it  on  the  side  of  the  desired  resistance.  However, 
even  when  several  teeth  thus  aid  in  offering  resistance  to 
the  force  applied,  all  of  them  will  often  yield  somewhat  to 
the  pressure  and  become  inclined  from  their  vertical  posi- 
tions, because  each  one  has  an  independent  movement,  and 
frequently  the  main  anchor  tooth  will  be  slight!}7  elevated 
from  its  socket.  Many  cases  of  attempted  regulating  in  this 
way  have  resulted  in  failure,  because  after  the  teeth  used  for 
resistance  had  moved  and  become  loose  they  could  no  longer 
be  used  as  anchorage. 


hO  ORTHODONTIA. 

While  there  should  be  little  excuse  for  ever  using  a  single 
tooth  for  anchorage  on  account  of  the  almost  certainty  of 
FIG  18         tipping,  the  tendency  may  be  largely  hindered 
and  sometimes  prevented  by  soldering  a  long 
tube  to  the  band  instead  of  a  short  one. 

DFig.  18  illustrates  this. 
With  a  short  tube  tipping  may  easily  occur 
on  account  of  the  slight  resistance  offered,  but 
—     with  a  long  one  any  tendency  to  tip  would  be 
checked  by  the  long  bearing  which  the  tube 
has  upon  the  bar  or  rod  which  passes  through  it. 

Reinforced  Anchorage. — The  method  of  joining  together 
two  or  more  teeth  by  metal  bands  soldered  together  does 
away  with  individual  movement,  for  by  this  plan  no 
tooth  can  move  independently  of  the  others,  nor  can  any  of 
them  be  tipped  from  their  vertical  positions.  Either  all  of 
the  teeth  included  in  the  anchorage  will  be  dragged  through 
the  alveolar  process  in  their  upright  positions  or  by  their 
united  resistance  they  will  be  able  successfully  to  oppose 

the  force  applied  to  them.  The 
latter  will  naturally  be  the 
result. 

The  principle  involved  is  well 
shown  in  Fig.  19,  where  two 
molars,  joined  by  united  bands, 
offer  resistance  to  force  applied 
in  the  moving  of  a  cuspid  tooth. 
If  the  force  were  exerted  in  an 
opposite  direction  for  moving  the 
cuspid  forward  there  would  be 
little  need  for  united  bands,  in- 
asmuch as  the  molar  used  for 
anchorage  would  be  sufficiently 
supported  by  the  tooth  and  tuberosity  back  of  it. 

Resistance  somewhat  analogous  to  the  foregoing  may  be 
obtained  by  swaged  metal  caps  to  cover  the  occlusal  sur- 


DYNAMICS    OF    TOOTH    MOVEMENT.  61 

faces  and  part  of  the  crowns  of  the  anchor  teeth,  soldering 
them  together  and  cementing  them  in  position  after  the 
necessary  attachments  have  been  made. 

This  plan  is  particularly  good  where  it  becomes  necessary 
touse  deciduou  steeth  for  purposes  of  anchorage.  Two,  or 
preferably  three  of  them  joined  in  this  manner  will  often 
furnish  abundant  resistance  for  any  proposed  ordinary 
movement  where  it  would  be  absolutely  unsafe  to  use  one 
of  them  singly. 

The  Jackson  wire-crib  is  an  admirable  anchorage  device 
because  it  offers  the  combined  resistance  of  several  teeth  in 
the  moving  of  others.  All  of  these  methods  are  valuable 
and  oftentimes  one  is  more  available  than  any  of  the  others 
but  none  of  them  furnishes  the  same  degree  of  resistance  as 
is  secured  by  united  metal  bands  attached  to  permanent 
molar  teeth. 

Where  two  molar  teeth  need  to  be  used  for  anchorage, 
and  the  posterior  one  is  not  suitable  for  banding,  owing 
possibly  to  incomplete  eruption,  they  can  be  joined  in 
another  way. 

Fig.  20  is  an  illustration  of  the  manner  in  which  the 
preceding  conditions  were  F  2Q 

met  by  the  author  in  a  few 
instances.  A  band  was 
made  for  the  first  molar, 
and  to  the  middle  of  its  dis- 
tal surface  was  soldered  a 
section  of  screw-wire  bent 
at  a  right  angle  at  a  point 
suitable  to  fit  into  the  an- 
terior occlusal  pit  of  the 
second  molar  which  was 

enlarged  for  its  accommodation.  Cemented  into  place  it 
held  the  two  molars  rigidly  together. 

A  vulcanite  plate  covering  the  roof  of  the  month  has 
been  and  still  is  preferred  by  some  as  a  means  of  resistance 


62 


ORTHODONTIA. 


FIG.   21. 


to  applied  force,  because  by  its  impingement  upon  many 
teeth  the  resistance  is  distributed  over  a  large  area,  and  is 

not  great  at  any  one 
point.  It  is,  proba- 
bly, the  least  valua- 
ble of  all  devices  for 
offering  resistance 
because  of  its  lia- 
bility to  displace- 
ment, and  the  con- 
sequent uncertainty 
of  good  results. 

When  it  is  desired 
to  move  a  tooth 
either  labially  or 
lingually  the  resist- 
ance to  the  applied 
power  will  usually 
have  to  be  secured 

at  a  point  on  the  opposite  side  of  the  arch,  and  as  in  other 
cases  be  obtained  by  combining  the  resistance  of  several 
teeth. 

Fig.  21  shows  how  by  the  use  of  a  single  band  with  a  bar 

attached  extending 
along  and  touching  the 
two  adjoining  teeth, 
the  resistance  of  three 
teeth  is  offered  to  the 
moving  of  a  cuspid  on 
the  opposite  side  of  the 
arch.  This  method  is 
exceedingly  valuable 
where  the  teeth  on  the 
anchorage  side  of  the 
arch  are  in  such  close 

contact  as  scarcely  to  admit  of  the  employment  of  more 
than  one  band. 


FIG.  22. 


DYNAMICS   OF    TOOTH    MOVEMENT. 


63 


Another  illustration  of  the  same  principle,  differently 
applied,  will  be  seen  in  Fig.  22,  where  by  the  use  of  a  single 
band  and  ex  tension- wire,  five  teeth  are  made  to  offer  resist- 
ance in  the  moving  of  an  opposite  cuspid. 

Reciprocal  Anchorage. — This  method  of  applying  two 
opposing  forces  to  an  anchor  tooth,  and  thus  preventing  it 
from  changing  its 

position  is  an  ex-  '  TTV--,^  .  FIG.  23. 
tremely  valuable 
one  where  the  con- 
ditions are  favora- 
ble for  its  employ- 
ment. The  prin- 
ciple involved  is 
illustrated  in  Fig. 

23,  where  the  force  applied  for  the  moving  |of  the  root  of  a 
tooth  is  opposed  by  a  bar  attached  near  the  incisal  edge  of 
the  crown  operating  in  an  opposite  direction.  If  the  two 
forces  be  equal  the  anchor  tooth  or  teeth  will  not  be  moved. 
The  same  result  would  follow  if  the  lower  or  incisal  bar 
remained  stationary  while 
force  was  exerted  upon  the 
upper  one  or  vice  versa. 

Fig.  2i  is  another  illus- 
tration of  the  same  princi- 
ple. The  appliance  is  de- 
signed to  move  the  lower 
centrals  labially,  and  the 
laterals  lingually.  The 
inner  bar  in  moving  the 
centrals  labially  exerts  a 
backward  force  against  the 

molars  used  for  anchorage  while  the  outer  bar  in  forcing 
the  laterals  lingually  exerts  an  equal  forward  force  upon 
the  same  molars.  These  opposing  forces,  supposedly  equal, 
should  prevent  the  anchor  teeth  from  moving  either  forward 
or  backward. 


FIG.  24. 


64 


ORTHODONTIA. 


FIG.   25. 


Intermaxillary  Anchorage. — This  newest  and  most  valuable 
form  of  pitting  the  resistance  of  the  teeth  of  one  jaw  against 
those  of  the  other  by  the  use  of  elastic  rubber  rings  was  first 
devised  and  used  by  Prof.  C.  S.  Case,  and  by  him  published 
to  the  world  in  1893.*  According  to  the  manner  in  which 
it  is  employed  it  may  be,  on  occasion,  an  anchorage,  a 
reciprocal  intermaxillary  force,  or  an  adjunct  to  other  devices. 

When  used  as  an  an- 
chorage, all  of  the  teeth 
in  the  jaw  that  is  to  offer 
resistance  must  take  part 
in  the  work,  and  to  do 
this  each  tooth  must  be 
surrounded  by  a  band  with 
suitable  attachments  for 
holding  a  bow- wire  pass- 

^ _^ ing   around   the   arch    as 

shown  in  Fig.  25.     Over 
the  distal  end  of  the  bow- 
wire   where    it  protrudes  from  the  tubing  on  the  molars, 
a  ring  of  rubber  is  slipped  and  carried  to  a  hook  on  a  bow- 
wire  or  other  device  attached  to  one  or  several  teeth  in  the 

opposite  arch  intended  to 
be  moved  distally.  The 
greater  number  of  anchor 
teeth  in  the  one  arch  will 
resist  the  force  thus  ap- 
plied to  the  fewer  teeth  in 
the  other. 

Fig.  26,  represents  a 
more  complicated  appli- 
ance of  the  same  general 
character,  but  by  its  ar- 
rangement of  single  molar 

tubes   and   adjustable   nuts    operating    upon    a    bow-wire 
which  passes  freely  through  these  tubes,  the  design  being  to 

*  Dental  Review,  March  1893. 


FIG.  26. 


DYNAMICS    OF    TOOTH    MOVEMENT.  65 

move  forward  first  the  lower  incisors,  next  the  bicuspids, 
and  then  the  molars. 

The  elastic  ring  in  this  case,  as  before,  engages  with  a 
hook  soldered  to  the  last  molar  tube,  as  shown  at  H.  A.,  and 
is  then  carried  to  a  hook  above  attached  to  a  bow-wire, 
which,  passing  through  individual  band  attachments  on 
each  of  the  upper  teeth  (or  as  many  as  may  be  necessary) 
secures  their  combined  resistance. 

If  it  were  attempted  to  move  all  of  the  lower-teeth  for- 
ward at  the  same  time,  and  not  the  mandible,  by  this  last 
arrangement,  the  result  would  be  a  failure  as  the  force 
exerted  at  each  end  of  the  elastic  ring  would  be  about  equal. 
Other  ways  of  employing  the  intermaxillary  principle  will 
be  considered  in  the  chapters  in  Part  III,  devoted  to  Pro- 
trusions, Retrusions  and  Nonocclusion. 

Occipital  Anchorage. — Though  its  range  of  usefulness  is 
somewhat  limited  it  would  be  hard  to  overestimate  the  value 
of  Occipital  Anchorage.  The  dome  of  the  head  not  only 
furnishes  an  anchorage  outside  of  the  mouth  as  none  other 
does,  but  provides  one  that  is  absolutely  stable  and  capable 
of  offering  resistance  to  far  greater  force  than  could  possibly 
be  employed  in  the  movement  of  either  teeth  or  mandible. 
It  may  be  used  in  connection  with  the  retrusion  of  either 
upper  or  lower  teeth  in  phalanx ;  the  retrusion  of  the  man- 
dible ;  the  correction  of  anterior  non-occlusion,  and  possibly 
in  other  cases  where  great  force  is  to  be  applied  and  where 
opportunity  for  sufficient  anchorage  cannot  be  found  within 
the  oral  cavity. 

Proper  Application  of  Force. — When  power  is  to  be  applied 
for  the  moving  of  a  tooth,  attachment  for  the  purpose 
must  be  made  to  some  portion  of  the  crown,  as  that  is  the 
only  part  available.  Resistance  to  such  movement  is  fur- 
nished by  the  alveolus,  and  especially,  when  the  movement 
is  in  a  labial  or  lingual  direction,  by  the  harder  cortical 
layer  covering  the  alveolar  plates.  The  alveolar  tissue 
about  the  root  and  especially  toward  the  apex  being  open 


66  ORTHODONTIA. 

and  spongy  and  the  cervical  portion  of  the  root  almost  in 
contact  with  the  dense  cortex,  it  follows  that  the  pivotal 
part  of  the  tooth  must  be  nearer  this  latter  surface,  in  a 
labial  or  lingual  movement. 

Where,  however,  the  movement  is  in  the  direction  of  the 
arch  line,  there  being  no  cortical  covering  to  the  septa,  and 
the  latter  being  thinest  at  the  cervical  margin  the  fixed 
point  of  the  root  would  be  nearly  or  quite  at  the  apex  where 
the  cancellate  tissue  is  greatest. 

As,  therefore,  in  the  ordinary  movement  of  a  tooth  we 
have  a  resistance  to  be  overcome,  a  force  exerted  to  over- 
come such  resistance  and  a  fulcrum  or  point  of  relative 
immobility,  it  is  evident  that  the  tooth  in  its  movement 
becomes  a  lever. 

A  lever  is  described  as  "  any  rigid  bar,  straight  or  bent, 

resting  on  a  fixed-  point  or  edge,  called  a  fulcrum."     The 

forces  acting  on  the  lever  are  the  weight  or  resistance  (W), 

the  power  (P),  and  the  reaction  of  the  fulcrum  (F).     Levers 

are  divided  into  three  classes.    In  the  first-class,  the  fulcrum 

FIG.  27.  (F)  is  situated  between  the  power 

w      (P)  and  the   weight  (W),  as  in   a 

PI  *  ^        — 4H1    crow-bar  or  a  child's  see-saw.     In 

the  second  class  the  weight  (W)  is 
between   the  power  (P)  and   the 
„      fulcrum  (F),  as  in  a  wheelbarrow 
or  a  door.     In  the  third  class  the 
Lexers.  power  (P)  is  between  the  fulcrum 

(F)  and  the  weight  (W)  as  in  a  pair  of  tweezers  or  the 
human  forearm.  The  three  forms  of  the  lever  are  shown  in 
Fig.  27. 

In  the  movement  of  a  tooth  labially  or  lingually  the 
principle  involved  is  that  of  a  lever  of  the  first-class,  the  dis- 
tance from  P  to  F  representing  the  crown,  that  from  F  to  W 
the  root,  and  F  the  cortical  layer  of  the  alveolus.  If,  by  any 
means,  we  can  lessen  the  distance  between  F  and  W  or 
increase  that  from  F  to  P  we  will  gain  a  corresponding 


DYNAMICS   OF   TOOTH    MOVEMENT.  67 

advantage,  for  on  the  principle  of  the  lever  (when  there  is 
equilibrium)  "  The  power  arm  is  to  the  weight  arm  as  the 
weight  is  to  the  power."  In  dia-  FlQ  2g 

gram    Fig.  28,  if  we   desire   to  p, p w 

raise  a  weight  of  20  Ibs.  at  W  F 

We     Can     do     SO    by    applying     a    Region  between  Power  and  Weight. 

downward  force  of  20  Ibs.  at  P,  since  P  arid  W  are  equidis- 
tant from  F,  but  if  we  apply  our  power  at  P'  a  force  of  10 
Ibs.  will  accomplish  the  same  result  because  the  distance 
from  P'  to  F  is  twice  as  great  as  the  distance  from  W  to  F. 
Expressing  it  in  a  formula,  we  have  P'F :  \VF : :  W :  P'  or 
2:  1::  20:  10. 

In  moving  a  tooth  anteriorly  or  posteriorly  in  the  alveo- 
lar arch  the  tooth  becomes  a  lever  of  the  second  class 
because  the  fulcrum  is  near  the  apex,  and  the  resistance  W 
between  it  and  the  power. 

In  any  attempt  to  move  the  crown  of  a  tooth,  force  should 
be  applied  as  near  the  occlusal  surface  as  possible.  Con- 
versely when  we  desire  to  use  a  tooth  for  anchorage,  our 
attachment  should  be  made  close  to  the  cervical  margin  for 
we  thus  shorten  the  distance  between  the  power  and  the 
fulcrum  and  correspondingly  lessen  the  liability  of  moving 
the  tooth. 

When  we  desire  to  move  the  root  of  a  tooth  without  mov- 
ing the  occlusal  portion  of  the  crown,  we  must  do  so  on  the 
principle  of  a  lever  of  the  third  class.  The  fulcrum  F  must 
be  close  to  the  occlusal  surface  and  the  power  P  applied  as 
near  to  the  cervical  margin  as  possible  in  order  that  the 
resistance  W  may  be  overcome  with  the  least  expenditure  of 
force,  and  in  the  shortest  possible  time.*  To  secure  a  ful- 
crum at  the  occlusal  surface,  it  is  necessary  to  have  a  band 
attached  to  the  crown  at  this  point  and  by  some  means  con- 
nect this  band  with  the  anchorage. 

Prof.  C.  S.  Case  was  the  first  to  show  that  in  a  movement 

*  It  should  be  borne  in  mind  that  in  all  cases  W  represents  the  resistance  to  be  over- 
come and  that  with  a  tooth  the  roots  are  simply  one  arm  of  a  lever.  The  actual  resist- 
ance is  the  alveolar  tissue  surrounding  the  root. 


68  ORTHODONTIA. 

of  this  or  any  similar  kind  great  advantage  is  gained  by 
applying  the  power  at  some  point  opposite  the  root  instead 
of  upon  the  crown.  His  method  of  doing  this  is  to  solder 
a  short  rigid  bar  to  the  band  surrounding  the  tooth  to  be 
FIG.  29.  moved  and  to  have  this  bar  extend  outside 
of  the  gum  in  the  direction  of  the  root  as  far 
as  the  lip  or  other  tissues  will  permit,  as 
shown  in  Fig.  29.  By  this  plan  the  force  is 
applied  nearer  to  the  end  of  the  root  and 
8  "~""*^  farther  from  the  cervical  margin  (fulcrum) 

thus  greatly  increasing  the  leverage.  How 
Bar  Extension  for  force  applied  at  the  free  end  A  of  the  bar 
increased  Leverage  can  operate  to  greater  advantage  in  moving 
the  root  than  if  applied  at  the  point  B  of  the  band  where 
the  bar  is  attached,  may  be  best  understood  by  reference  to 
the  diagram.  Fig.  30. 

Let  A  D  represent  a  lever  with  a  fulcrum  at  F.    To  this  is 
firmly  attached  another  rigid  rod,  B  C.    It  is  evident  that  any 
FIG-  30.  force  applied  to  the  arm  F  D 

in  one  direction  will  cause 
the  other  arm,  A  F,  to  move 
in  the  opposite  direction  on 
the  principle  of  a  lever  of  the  first  class ;  but  since  the  two 
rods,  B  D  and  B  C,  are  rigidly  united,  they  must  act  in  uni- 
son, so  that  a  force  exerted  at  any  point  along  f  C  will  cause 
the  arm  F  D  to  move  in  the  same  direction  and  A  F  to 
move  in  the  opposite  one.  Thus  we  see  that  the  motion  of 
F  A  is  the  same  whether  we  apply  the  power  along  f  C  or 
along  F  D,  and  conversely,  power  applied  in  one  direction 
at  any  point  of  the  arm  F  A  will  cause  both  f  C  and  F  D  to 
move  in  the  opposite  direction.  On  the  same  principle  any 
force  applied  at  C  in  the  direction  E  C  will  be  correspond- 
ingly felt  along  the  line  F  D.  Whether  the  bar  B  C  be 
straight,  curved  or  angular  will  make  no  difference  provided 
it  be  rigid.  Applying  these  principles  to  the  moving  of  a 
tooth  in  its  socket  it  will  be  apparent  that  any  force  applied 


DYNAMICS    OF    TOOTH    MOVEMENT. 


69 


Principle  of  Increased 
Leverage. 


above  the  alveolar  border,  as  at  C  (Fig.  31),  will  tend  to  move 
the  root  F  D  in  the  same  direction,  whether  it  be  labially  or 
lingually,  for  it  is  equivalent  to  apply- 
ing the  force  directly  to  the  root  itself. 

Of  the  different  mechanical  powers 
several  are  employed  to  a  greater  or 
less  extent  in  the  regulation  of  teeth, 
although  the  greatest  efficiency  is  ob- 
tained from  the  screw. 

The  Lever. — The  principle  of  the  lever 
is  not  often  embodied  in  a  regulating  ap- 
pliance, both  on  account  of  its  inappli- 
cabili^y  and  because  other  forms  of  ap- 
plying forceserve  us  to  better  advantage. 

It  might  seem  as  though  the  appliance  shown  in  Fig.  32 
operated  upon  the  principle  of  a  lever,  and  so  it  would  if  the 
extension  bar  were  perfectly  rigid,  but  as  it  is  always  some- 
what flexible,  being  made  of  springy  metal,  it  is  in  reality 
a  spring  and  operates 
accordingly. 

The  Inclined  Plane. — 
This   is    used    only   in 
very  rare  instances,  al- 
though where  applica- 
ble its  efficiency  is  very 
great.  In  certain  simple 
forms  of   malocclusion 
an  appliance    embody- 
ing   this    principle   is   applied   to    teeth    in    one    jaw   in 
order  to  change  the  position   of  a  tooth   in  the  opposite 
one.      Occasionally,    also,   a   vulcanite    or   metal   plate   is 
made   with   a  portion   of  it   arranged  in  the  form  of  an 
inclined  plane  to  aid  in  changing  the  bite  or  occlusion  of 
the  teeth  in  the  opposite  jaw.     Objection  to  this  method  of 
applying  force  lies  in  the  fact  that  it  is  operative  only  when 
the  jaws  occlude,  and  this  the  patient  can  and  often  will 


FIG.  32. 


70  ORTHODONTIA. 

prevent  except  during  the  short  periods  of  mastication.    It  is 
therefore  not  only  a  slow  method,  but  a  very  uncertain  one. 

The  Wedge. — Pieces  of  elastic  rubber  or  of  compressed 
wood  inserted  between  the  teeth  or  between  an  appliance 
and  a  tooth  are  usually  spoken  of  as  wedges,  but  they  are 
not  such  in  reality.  They  operate  by  virtue  of  their  resil- 
iency or  elasticity — that  is,  the  force  is  derived  from  the 
substance  resuming  the  form  it  possessed  before  being  com- 
pressed. Strictly  speaking,  the  principle  of  the  wedge  has 
never  been  employed  in  the  moving  of  malposed  teeth. 

The  Screw. — The  screw  is  a  combination  of  the  inclined 
plane  and  lever.  Two  inclined  planes,  one  on  the  screw 
and  one  on  the  nut,  play  upon  each  other  and  are  operated 
by  a  lever.  Its  slow  movement,  together  with  its  direct 
delivery  of  force  and  positive  action,  constitute  it  the  best 
form  of  mechanical  power  for  use  in  the  mouth  when  con- 
ditions favor  its  employment.  Usually  both  screw  and  nut 
are  of  metal,  but  sometimes  the  metallic  screw  is  made  to 
operate  in  a  threaded  hole  in  a  vulcanite  plate.  In  no  other 
form  of  instrument  is  the  application  of  force  so  completely 
under  the  control  of  the  operator,  and  one  of  its  great  advan- 
tages is  that  it  can  be  operated  by  the  patient  himself.  Its 
wide  range  of  applicability  easily  places  it  at  the  head  of 
the  list  of  devices  for  the  moving  of  teeth. 

Elasticity. — Less  valuable  than  the  screw,  but  probably 
more  valuable  than  any  other  method  of  applying  power, 
is  elasticity.  The  force  obtained  through  its  agency  is 
less  direct  and  positive  than  that  of  the  screw,  but  it  can 
often  be  employed  to  advantage  when  the  latter  cannot  and 
hence  is  most  serviceable  in  applying  force  to  malposed 
teeth.  It  is  usually  employed  in  the  form  of  a  bar,  bow  or 
spring  of  some  metal  or  its  alloys,  though  its  power  is  also 
utilized  through  the  agency  of  elastic  rubber  and  vulcanite, 
wood  and  other  substances. 

Character  of  Resistance  to  be  Overcome. — We  have  already 
spoken  of  the  general  structure  of  the  alveolar  process,  but 


DYNAMICS    OF    TOOTH    MOVEMENT.  71 

in  order  to  obtain  a  clearer  understanding  of  the  character 
of  resistance  it  offers  to  the  movement  of  the  different  teeth, 
it  will  be  necessary  to  notice  certain  peculiarities  of  this 
structure  at  various  points  of  the  alveolar  arch. 

On  a  careful  examination  of  the  superior  maxilla,  we  will 
notice  that  in  the  incisor  region  the  outer  plate  of  the  alveo- 
lar process  is  exceedingly  thin  and  conforms  so  closely  to 
the  roots  of  the  teeth  as  to  distinctly  outline  their  form  and 
extent.  This  thinness  of  the  plate  is  due  to  the  fact  it 
is  composed  almost  entirely  of  the  cortex,  there  being  very 
little  cancellate  tissue  underlying  it.  Proceeding  backward 
we  find  this  outer  plate  gradually  increasing  in  thickness  to 
the  second  and  third  molars. 

With  the  inner  or  lingual  plate  it  is  different.  In  the 
incisor  region,  while  it  is  attenuated  at  the  alveolar  border, 
it  rapidly  increases  in  thickness  in  the  direction  of  the  roots 
on  account  of  the  cortical  layer  sloping  off  to  form  the  pal- 
ate. This  is  equally  true  of  that  portion  lying  next  to  the 
bicuspid  and  molar  teeth. 

Fig.  33  represents  a  section  of  the  supe-         Fl»-  33- 
rior  maxilla  adjoining  the  median  line.     B 
is   the   alveolus   or   socket    of    the   central 
incisor.     A  and  C  show  the  relative  thick-, 
ness  of  the  cortex  composing  the  external 
alveolar  plate,  with  very  little  cancellate  tis- 
sue underlying  it,     E  represents  the  thick    section  through  su- 

„     ^       .  ,  ,  ,       perior   Alveolar  Pro- 

cortex  01  the  inner  plate,  not  only  near  the  cess  near  Median  Line 
alveolar  border,  but  in  its  continuation  to 
form  the  palate,  while  D  indicates  the  large  amount  of  can- 
cellate tissue  at  the  base  and  inner  portion  of  the  alveolus. 

It  will  thus  be  seen  that  owing  to  the  varying  character 
of  resistance  offered,  certain  movements  of  the  upper  incisor 
teeth  are  more  readily  accomplished  than  others. 

The  outward  movement  of  an  incisor  crown  is  effected 
with  comparative  ease,  because  the  outer  alveolar  plate  being 
thin  and  elastic,  bends  in  response  to  pressure,  while  the 


72  ORTHODONTIA. 

apical  end  of  the  root,  tending  to  move  in  an  opposite  direc- 
tion, presses  upon  the  cancellate  tissue  on  its  inner  surface, 
which  is  readily  broken  down  and  resorbed. 

The  inward  movement  of  the  same  crown  is  accomplished 
with  somewhat  greater  difficulty  because  there  is  very  little 
yielding  of  the  inner  alveolar  plate,  owing  to  its  mass  and 
solidity.  Thus,  while  the  crown  moves  lingually  and  the 
root  labially,  the  cervical  portion  scarcely  changes  its  posi- 
tion at  all. 

In  nearly  all  cases  of  upper  protrusion  there  is  a  lack 
of  fulness  under  the   upper   portion    of   the  lip,  and  the 
improvement  of  facial  harmony  following  the  correction  of 
the  deformity  is  due,  in  great  part,  to  the  labial  movement 
of  the  apical  ends  of  the  roots,  which  must  necessarily  accom- 
pany the  lingual  movement  of  the  crowns.    This  is  equally 
true,  though  to  a  lesser  extent,  in  similar  movements  of  the 
bicuspids.     In  the  upper  molar  region  both  alveolar  plates 
are  so  thick  that  it  is  doubtful  whether  they  bend  under 
pressure  to   any  appreciable  extent.      The 
FIG.  34.          movement  of  these  teeth  in  an  outward  direc- 
tion is  probably  accomplished  only  through 
the  slow  process  of  resorption,  or  by  a  sepa- 
ration of  the  two  halves  of  the  palate  at  the 
median  suture.    In  the  lower  jaw,  there  being 
no  palate,   the   thickness  and  structure  of 
both  the  external  and  internal  plates  in  the 
incisor  region  are  very  similar,  which  ac- 
counts for  the  equal  facility  with  which  an 
incisor  may  be  moved,  either  in  a  labial  or 
section  through   lingual    direction.     Fig.  34   illustrates  this 

Inferior      Maxilla 

near  Median  Line,  condition,  the  lettering  of  the  parts  being 

similar  to  that  in  Fig.  33. 

In  the  molar  (and  partly  in  the  bicuspid)  region  of  the 
lower  alveolus,  the  teeth  are  even  more  immovably  fixed 
than  in  the  upper,  owing  to  the  greater  thickness  and 
prominence  of  both  alveolar  plates.  Great  force  applied  to 


DYNAMICS   OF    TOOTH    MOVEMENT.  73 

move  the  lower  molars  outwardly  can  accomplish  its  object 
only  by  slow  resorption. 

A  marked  peculiarity  of  the  cortical  layer  of  both  upper 
and  lower  maxillae,  is  that  while  it  partly  encircles  the 
teeth  at  their  cervical  margins,  it  does  not  cover  the  free 
edges  of  the  septa.  This  accounts  for  the  fact  that  teeth  are 
much  more  readily  moved  either  forward  or  backward  in 
the  line  of  the  arch  than  in  a  direction  at  right  angles 
to  it.  The  septa  being  composed  entirely  of  loose  can- 
cel late  tissue,  its  resorption  readily  takes  place.  It  also 
explains  the  tendency  of  anchor  teeth  to  change  their  posi- 
tions in  response  to  pressure  exerted  in  the  line  of  the  arch. 


PART  II. 


PRACTICAL   CONSIDERATIONS. 
CHAPTER  I. 

PRELIMINARIES  AND  STUDY  OF  CASE. 

Examination. — When  a  case  of  irregularity  presents  for 
treatment  or  consultation  the  first  requirement  is  a  careful 
examination  of  the  mouth  and  teeth. 

In  making  this  examination  it  is  necessary  to  note  the 
position  of  the  teeth,  their  relation  to  one  another,  their 
occlusion  with  those  of  the  opposite  jaw*,  the  relative  size 
and  shape  of  both  arches,  the  size,  character  and  condition 
of  the  teeth,  the  age  and  general  health  of  the  patient, 
the  harmony  or  inharmony  of  the  features  and  the  facial 
expression. 

This  preliminary  examination  will  enable  us  to  form  an 
opinion  as  to  the  difficulties  of  the  case,  the  amount  of 
improvement  that  can  be  made,  the  probable  time  that  will 
be  required  and  an  approximate  estimate  of  the  cost. 

A  little  experience  will  enable  us  to  determine  quickly 
what  we  can  do  and  what  difficulties  present,  but  we  should 
be  very  guarded  in  making  any  statement  as  to  time 
required,  the  cost  of  the  operation,  or  the  appliances  which 
we  propose  to  use.  These  last  three  points  can  only  prop- 
erly be  determined  after  the  final  study  of  the  case. 

While  assuring  the  parent  or  patient  of  what  we  shall 
probably  be  able  to  accomplish,  we  should  at  the  same  time 
mention  that  the  appliances  may  cause  some  annoyance 
and  possibly  some  slight  pain,  and  that  patience,  endurance 

74 


PRELIMINARIES.  75 

and  perseverence  will  be  necessary  on  the  patient's  part  to 
enable  us  to  accomplish  a  satisfactory  result. 

It  should  also  be  made  clear  that  the  parent  or  patient  is 
expected  to  assist  in  the  furtherance  of  the  work  by  seeing 
that  the  appliances  are  faithfully  worn,  that  all  of  the 
instructions  are  carried  out,  that  the  patient  keep  all 
appointments  and  in  case  of  any  mishap  shall  report  at  the 
office  in  the  shortest  possible  time  after  its  occurrence. 

Should  the  prognosis  of  the  case  prove  satisfactory  and 
all  of  the  above  conditions  be  agreed  to,  we  may  at  once 
proceed  with  the  treatment. 

Impressions. — The  first  step  will  be  to  take  impressions  of 
the  upper  and  lower  teeth,  including  as  much  of  the  tissues 
overlying  the  roots  as  possible.  These  impressions  should 
be  as  perfect  as  they  can  be  made,  in  order  that  the  subse- 
quent models  may  enable  us  to  study  the  case  to  the  best 
advantage. 

Trays. — The  best  impression  trays  are  those  made  from 
aluminum.  A  variety  of  sizes  should  be  kept  on  hand  and 
all  should  be  of  the  flat  bottom  kind,  as  these  afford  better 
accommodation  for  the  crowns  of  the  teeth.  In  addition, 
they  should  have  high  sides,  so  as  to  carry  the  material  as 
well  up  on  the  gums  as  possible. 

Impression  Materials. — Of  these  we  have  at  present  two 
that  serve  our  purpose  very  well.  They  are :  Plaster  and 
Modeling  Compound. 

Plaster  of  Paris. — This  substance,  so  universally  used  for 
impressions  in  prosthetic  work,  is  generally  regarded  as  the 
most  desirable  for  Orthodontia  impressions  and  models.  Its 
advantages  are  the  accuracy  and  sharpness  of  the  resultant 
impression  and  its  perfect  freedom  from  any  possible  change 
or  distortion  in  removing  it  from  the  mouth. 

As  disadvantages,  we  have  its  disagreeableness  to  the 
patient,  the  difficulty  of  removal  with  its  attendant  fracture, 
and  the  tediousness  of  separating  the  impression  from  the 
model. 


76  ORTHODONTIA. 

In  spite  of  these  objections,  however,  its  accuracy  of 
results  overbalances  them  all  and  places  it  at  the  head  of 
the  list  of  substances  used  for  impressions.  The  proper 
method  of  manipulating  it  is  familiar  to  all  practitioners 
who  do  prosthetic  work.  The  one  essential  point  in  which 
plaster  impressions  for  orthodontic  work  differ  from  those 
taken  for  the  making  of  artificial  dentures  is  that  in  the 
former  more  importance  is  attached  to  an  accurate  imprint 
of  the  teeth  and  gums  than  in  the  latter. 

For  this  reason,  in  placing  the  mixed  plaster  in  the  tray 
for  an  upper  impression  it  should  be  well  built  up  at  the 
front  and  sides  and  little  attention  be  paid  to  the  center. 
The  vault  will  usually  be  filled  by  the  surplus,  but  if  it  is 
not  it  will  matter  little. 

As  in  the  taking  of  all  impressions,  after  the  material 
has  been  introduced  into  the  mouth  and  pressed  into  place, 
the  lip  and  cheeks  should  be  drawn  out  and  pressed  back  and 
the  tray  then  immovably  held  until  the  plaster  has  fully  set, 
when  it  can  be  removed  by  the  force  of  the  two  thumbs  on 
the  top  edge  of  the  impression  in  the  region  of  the  bicuspid 
teeth  on  each  side.  This  will  cause  it  to  fracture  irregu- 
larly, but  the  pieces,  after  washing  and  drying  thoroughly, 
can  all  be  placed  in  proper  position  in  the  tray  and 
retained  by  melted  hard-wax  applied  with  a  spatula  at 
suitable  points. 

Another  and  better  way  of  removing  the  plaster  impres- 
sion is  to  first  remove  the  cup  (which  must  be  entirely 
smooth  on  its  inner  surface)  and  then  cut  a  groove  in  the 
plaster  down  to  and  along  the  occlused  surfaces  of  the  teeth 
from  molar  to  molar.  Two  supplemental  grooves  should 
also  be  cut  from  the  free  margin  of  the  impression  down  to 
the  cusps  of  the  cuspid  teeth.  The  two  buccal  and  the 
labial  sections  can  then  be  pried  off,  after  which  the  palatal 
portion  may  be  removed  in  one  piece.  After  washing  and 
drying,  the  four  pieces  are  replaced  in  the  tray  and  united 
to  one  another  and  to  the  tray  by  hard-wax,  as  before. 


PRELIMINARIES.  77 

In  taking  a  lower  impression,  in  addition  to  drawing  out 
the  lip  and  cheeks,  the  tongue  should  be  elevated  while  the 
plaster  is  still  soft  and  then  allowed  to  fall  back  into  place. 
This  will  prevent  folds  of  the  lip,  cheeks  and  sublingual 
tissues  being  included  in  the  impression. 

In  removing  a  lower  plaster  impression,  after  grooves 
have  been  cut  along  the  occlusal  surfaces  and  vertically 
over  the  cuspids,  the  outer  sections  are  removed  and  then 
the  long  lingual  portions  are  pressed  toward  one  another 
and  fractured  to  facilitate  their  removal. 

Modeling  Compound. — While  this  material  does  not  give 
as  sharp  an  impression  as  plaster,  it  will,  if  skilfully  manipu- 
lated, produce  results  that  are  very  satisfactory.  The  one 
objection  to  it  is  that  being  a  plastic  material  which  does 
not  become  entirely  hard  in  the  mouth  it  is  liable  to  suffer 
some  slight  distortion  in  removal.  While  this  would  con- 
stitute a  serious  objection  to  its  use  for  impressions  from 
which  a  plate  is  tb  be  made  it  is  far  less  objectionable 
when  employed  for  impressions  and  models  for  study 
purposes. 

In  use,  after  the  selection  of  a  suitable  tray,  a  proper 
quantity  of  the  compound  is  softened  by  dry  heat  or  in  hot 
water,  then  placed  and  properly  shaped  in  the  previously 
warmed  cup,  and  quickly  introduced  into  the  mouth. 

In  taking  an  upper  impression  the  mouth  should  be  well 
opened  so  that  the  teeth  may  not  come  in  contact  with  the 
material  before  the  proper  time,  and  thus  mar  the  surface. 
When  the  cup  with  its  contents  has  been  placed  as  far  back 
as  necessary,  and  immediately  beneath  the  teeth,  it  should 
be  brought  up  into  position  with  a  straight  and  steady 
movement.  Once  there,  it  should  be  firmly  held  while  all 
that  portion  along  the  outer  rim  is  pressed  against  the  teeth 
and  gums. 

In  this  position  it  must  remain  until  it  has  become  so 
hard  that  a  finger  nail  will  scarcely  indent  it,  when  it  should 
be  carefully  removed.  The  hardening  is  best  hastened  by 


78  ORTHODONTIA. 

a  stream  of  cold  water  from  a  syringe,  or  by  the  renewed 
application  to  the  cup  of  small  sponges  or  napkins  dipped 
in  ice  water. 

The  author  prefers  sections  of  absorbent  rolls  dipped  in  ice 
water  and  laid  under  the  cheeks  and  lips,  and  several  folds 
of  cottonoid  wet  with  ice-water  held  against  the  palatal  por- 
tion of  the  tray. 

All  of  these  are  renewed  several  times  until  'the  impres- 
sion is  well  chilled  when  it  can  be  removed  with  the  least 
possible  danger  of  drawing  or  dragging. 

For  an  impression  of  the  lower  jaw  the  same  general 
method  is  followed  and  after  the  tray  is  in  position  all  of 
the  surplus  material  around  both  the  outer  and  inner  rims 
should  be  pressed  into  place  with  the  finger. 

With  material  so  easily  manipulated  as  Modeling  Com- 
pound, and  so  unobjectionable  to  the  patient  it  is  well  to 
take  a  second  impression  of  the  arch  to  be  operated  upon  in 
order  to  have  a  working  model  or  one  upon  which  we  can 
construct  or  fit  our  bands  and  appliances.  Instead  of  this 
and  often  in  addition  to  it,  the  author  is  accustomed  to  take 
partial  impressions  of  those  portions  of  the  arch  upon  which 
appliances  are  to  be  fitted.  Models  made  from  these  are 
small,  convenient  to  handle  and  serve  an  excellent  purpose. 

During  the  same  sitting  at  which  the  impressions  are 
taken  the  manner  in  which  the  teeth  occlude  should  be 
carefully  noted,  and  a  memorandum  made  of  it  for  future 
use. 

Models. — Whether  partial  or  full,  all  models  should  be  as 
perfect  as  possible.  The  treatment  of  the  impression,  the 
pouring  of  the  model  and  the  subsequent  separation  of  the 
two  should  all  be  done  with  "the  greatest  nicety,  for  good  and 
accurate  models  are  the  foundation  upon  which  we  depend. 
Should  any  bubbles  or  air-holes  appear  in  'the  model  they 
may  be  filled  with  thinly-mixed  plaster  applied  with  a  fine 
camels-hairbrush  or  pencil  to  the  part  which  should  be  well 
saturated  with  water  beforehand. 


PRELIMINARIES.  79 

If  small  portions  of  the  plaster  teeth  happen  to  be  broken 
away  or  crushed  the  original  contour  may  be  restored  or 
built  up  with  the  brush  and  plaster  as  before.  Larger  por- 
tions of  teeth,  if  remaining  in  the  impression,  should  be 
carefully  removed,  and  cemented  into  place  on  the  model 
with  a  solution  of  celluloid,  made  by  dissolving  white  or 
colorless  celluloid  in  equal  parts  of  absolute  alcohol  and 
ether.  The  cement  should  be  of  about  the  consistency  of 
thick  cream,  and  both  portions  of  plaster  well  dried  before 
applying  it. 

Any  imperfections  having  been  remedied,  and  the  models 
suitably  trimmed  they  should  never  be  varnished,  for  even 
varnish  of  the  lightest  color  will  in  time  become  dark,  and 
therefore  unsightly.  However,  as  bare  plaster  models  soon 
become  soiled  in  handling,  they  may  be  protected  by  being 
immersed  for  five  minutes  in  hot  stearine  (stearic  acid).* 
The  models  should  be  entirely  free  from  moisture  and  well 
warmed  so  as  readily  to  absorb  the  preparation.  When 
removed,  no  free  stearine  will  be  found  upon  the  surface, 
and  by  rubbing  with  a  woolen  cloth  the  models  acquire  a 
high  polish,  and  assume  the  appearance  of  ivory. 

If  it  be  desired  to  photograph  the  models  it  must  be  done 
before  being  stearinized  because  afterward  the  reflection 
from  the  polished  surface  prevents  good  results. 

Upper  and  lower  models  may  be  placed  in  occlusion  and 
marked  with  a  pencil  at  one  or  two  opposite  points  as  guides 
in  subsequent  replacement  or  they  may  be  attached  to  an 
articulator  for  safer  handling  or  study. 

Loose  models  are  very  liable  to  be  injured  in  handling, 
especially  by  students  or  inexperienced  persons,  therefore, 
those  used  for  college  study  or  demonstration  had  better  be 
mounted.  An  original  model  once  injured  can  never  be 
duplicated,  and  hence  the  great  necessity  for  taking  unusual 
precautions. 

*  Stearine  should  always  be  melted  and  heated  in  a  water-bath  and  not  subjected 
to  direct  heat.    An  ordinary  tin-lined  glue-pot  answers  the  purpose  admirably. 


80 


ORTHODONTIA. 


An  inexpensive  and  excellent  articulator,  Fig.  35,  for  the 
mounting  of  models  of  irregularity,  is  made  from  brass  wire. 

The   upper 

FIG.  35.  j      -i 

arms  and  coil 

are  one  con- 
tinuous piece, 
while  the 
lower  arms 
are  formed  by 
passing  an- 
other piece 
of  the  wire 
through  the 
coil  and  bend- 
ing to  shape. 
The  artic- 
ulator is  so 
slender  in 
outline  that 
a  f t e  r  the 

models  are  attached  to  it  the  occlusion  of  the  inner  cusps  of 
the  teeth  may  be  as  readily  examined  as  that  of  the  outer 
ones. 

With  the  models  properly  arranged,  our  second  and  more 
deliberate  study  of  the  case  may  be  carried  forward  at  our 
leisure. 

At  the  first  or  personal  examination  of  the  case  we  are 
supposed  to  have  decided  upon  the  advisability  of  an 
attempt  at  correction,  and  also  upon  the  general  plan  we 
propose  pursuing.  By  the  study  of  the  articulated  models 
we  will  be  enabled  to  decide  upon  the  details  of  the  work 
and  the  kind  of  appliance  that  should  be  used.  Both 
studies  are  necessary,  for  with  the  patient  in  the  chair  we 
cannot  take  the  time  to  map  out  the  proposed  work  in  detail, 
while  an  examination  of  the  models  alone  will  leave  us  with- 
out a  knowledge  of  many  important  characteristics  of  the 
case  that  can  only  be  gained  from  a  personal  examination. 


The  Author's  Wire  Articulator. 


PRELIMINARIES.  81 

Accurate  models,  prepared  as  described,  are  most  impor- 
tant not  only  for  purposes  of  present  study,  but  also  for 
comparison  as  the  work  progresses.  Inasmuch  as  they 
represent  the  exact  condition  of  the  case  at  the  beginning, 
we  have  in  them  a  means  of  ascertaining  what  advance- 
ment has  been  made  at  any  stage  of  the  operation,  whether 
the  different  movements  are  proceeding  satisfactorily,  and 
finally,  when  the  operation  is  completed,  of  observing  just 
how  much  change  has  been  effected. 

When  the  case  is  completed  and  the  retaining  appliances 
removed  we  should  make  a  new  set  of  models  to  show  the 
result  of  our  operations.  The  two  sets  may  be  of  further 
advantage  to  us  in  case  of  any  legal  difficulties  or  if  the 
amount  or  character  of  our  services  should  be  questioned. 

Study  of  Case  From  Articulated  Models. — The  study  of  the 
case  may  be  either  a  simple  or  difficult  one,  according  to  the 
conditions  and  requirements  involved.  Thus,  the  move- 
ment of  a  single  tooth  usually  will  involve  only  the  con- 
sideration of  providing  accommodation  for  it  in  the  arch 
and  the  manner  of  applying  force  to  bring  it  into  position, 
whereas  when  a  number  of  teeth  in  different  locations  are 
to  be  moved,  each  perhaps  requiring  a  different  form  of 
movement,  we  will  have  to  decide  whether  we  can  and 
should  produce  all  of  these  movements  with  one  appliance 
at  one  time,  or  whether  it  would  be  best  to  .produce  each 
movement  separately  and  possibly  with  different  appliances. 
If  the  latter,  we  will  have  to  determine  which  should  be 
accomplished  first,  which  next,  and  so  on. 

In  attempting  to  produce  many  movements  with  one 
appliance  we  sometimes  defeat  our  object,  although  occa- 
sionally, as  in  arch  expansion  and  the  labial  movement  of 
individual  teeth,  all  may  be  accomplished  simultaneously 
with  the  bow  or  arch  wire  and  its  accessories.  Even  in  such 
case,  however,  it  is  best  not  to  attempt  too  much  at  one 
time,  for  with  many  teeth  in  movement  mastication  is  often 
imperfectly  performed. 


82  ORTHODONTIA. 

Having  decided  upon  the  order  in  which  the  movements 
should  take  place,  we  have  two  other  important  points  to 
determine. 

Amount  of  Force  Required. — This  will  be  determined 
largely  by  the  age  of  the  patient  and  the  character  of  the 
teeth  and  process.  As  previously  stated,  early  in  life,  before 
the  process  has  become  fully  calcified,  the  teeth  can  be 
moved  more  rapidly  than  at  a  later  period,  and  less  power 
will  be  required  to  accomplish  it;  so  also,  in  patients  of  the 
same  age,  the  teeth  of  one  will  be  more  readily  moved  than 
those  of  the  other.  This  is  due  both  to  the  relative  length 
of  the  roots  and  the  resistance  of  the  alveolar  walls  with 
their  dense  cortical  covering,  and  as  we  cannot  judge  of 
either  with  any  degree  of  exactness,  we  have  to  form  our 
opinion  from  the  general  conditions. 

Observation  has  shown  that  teeth  with  large  crowns,  situ- 
ated in  large,  firm  jaws,  usually  have  long  roots,  whereas 
smaller  teeth  associated  with  thin  and  more  delicate  pro- 
cesses have  shorter  roots. 

Therefore,  considering  the  age  of  the  patient  and  the 
appearance  of  the  teeth  and  processes,  we  can  at  least  decide 
whether  the  amount  of  force  to  be  applied  should  be  great 
or  little. 

Manner  of  Applying  Force. — Among  the  many  appliances 
or  substances  for  yielding  force  in  the  moving  of  teeth,  the 
practitioner  has  a  range  of  choice  from  the  screw  with  its 
directness  and  power,  to  the  silk  ligature  with  its  gentle 
traction.  In  the  use  of  any  of  these  it  is  necessary  that  they 
be  attached  to  the  anchor  teeth  in  such  manner  as  to  give 
us  greatest  efficiency.  The  best  means  of  securing  attach- 
ment for  fixed  appliances  is  by  means  of  bands  or  collars 
encircling  the  teeth  and  cemented  to  them,  or  in  other  cases, 
where  bands  are  to  remain  in  position  only  for  a  limited 
time,  the  screw  clamp-band  may  be  used. 

Uncemented  bands  remaining  on  the  teeth  for  a  period 
of  a  month  or  more  would  be  almost  certain  to  cause  injury 


PRELIMINARIES.  83 

to  the  enamel  through  the  fermentation  of  particles  of  food 
accumulating  under  the  bands  and  by  the  acidity  of  the 
saliva  in  a  state  of  rest.  Bands  cemented  to  the  teeth  with 
zinc-phosphate  are  entirely  free  from  this  danger  as  long  as 
the  cement  remains  intact. 

The  advantages  of  appliances  attached  to  the  teeth  in  this 
way,  over  removable  ones,  are : — 

1st.  The  leaving  of  the  roof  of  the  mouth  uncovered,  thus 
affording  more  room  for  the  movements  of  the  tongue. 

2nd.  Their  greater  cleanliness,  because  they  touch  the 
teeth  at  few  points,  and  thus  furnish  good  opportunity  for 
thorough  cleansing  with  the  brush. 

3rd.  Not  needing  to  be  removed,  fewer  visits  to  the  dentist 
are  necessary,  thus  effecting  a  great  saving  in  time  and  labor. 

4th.  The  patient  can  materially  assist  in  the  operation  by 
frequent  turning  of  the  nuts  which  nearly  always  form  a 
part  of  fixed  appliances. 


ESSENTIAL  QUALITIES  OF  AN  APPLIANCE. 

In  selecting  a  form  of  appliance  from  among  the  many 
that  have  been  devised  by  writers  and  workers  in  this  field 
of  practice,  or  in  devising  one  to  suit  the  demands  of  the 
case  under  consideration,  it  will  be  well  to  consider  and  bear 
in  mind  the  qualities  any  appliance  should  possess  in  order 
to  render  it  most  effective. 

The  following  are  among  the  most  important  of  such 
qualities : — 

Efficiency. — The  first  requirement  of  any  device  is,  that  it 
shall  be  able  to  do  the  work  expected  of  it.  All  appliances 
are,  of  course,  devised  with  this  end  in  view,  but  the  attain- 
ment of  it  is  often  not  as  simple  a  matter  as  might  at  first 
appear.  Almost  every  case  has  associated  with  it  so  many 
features  and  peculiarities  claiming  consideration,  that  even 
with  the  greatest  care  and  thought  we  often  fail  to  appre- 


84  ORTHODONTIA. 

hend  or  grasp  each  individual  complication.  Some,  indeed, 
are  so  little  apparent  that  they  can  scarcely  be  recognized 
in  advance. 

For  this  reason  even  the  most  experienced  practitioners 
will  at  times  devise  an  appliance  which,  though  seemingly 
meeting  all  the  requirements,  will,  when  brought  to  a  prac- 
tical test,  fail  to  accomplish  the  end  desired.  It  will  then 
have  to  be  altered  or  perhaps  discarded  in  favor  of  some 
other  fixture  more  perfectly  adapted  to  the  requirements  of 
the  case. 

An  appliance  that  does  not  yield  the  results  we  desire,  or 
which  yields  them  in  an  imperfect  manner,  should  in  all 
cases  be  superseded  by  another. 

Simplicity. — A  complicated  device  in  nearly  all  cases  is 
less  efficient  than  a  simple  one.  Simplicity  is  a  cardinal 
virtue  in  all  matters  of  construction,  and  through  lack  of  it 
about  ninety  per  cent,  of  the  patents  granted  in  this  country 
prove  unprofitable. 

Far  greater  mechanical  ingenuity  is  displayed  in  contriv- 
ing an  effective  simple  device  than  a  complicated  one. 

Rapidity  of  Action. — In  order  to  lessen  the  discomfort  of 
the  patient  and  to  conserve  the  time  of  both  patient  and 
operator,  a  regulating  appliance  should  be  as  rapid  in  its 
action  as  is  consistent  with  physiological  conditions.  Too 
rapid  action  may  cause  suffering  to  the  patient  and  possibly 
bring  about  deleterious  results,  while  too  slow  action  will 
prolong  the  treatment  unnecessarily  and  possibly  cause  the 
patient  to  become  disheartened  and  abandon  the  treatment. 

Between  these  two  extremes  there  is  a  mean  in  which  the 
best  results  are  accomplished. 

All  regulating  appliances  are  at  best  a  source  of  some  dis- 
comfort to  the  patient.  A  foreign  body  in  the  mouth,  occu- 
pying a  certain  amount  of  space  and  thereby  interfering 
more  or  less  with  natural  functions,  cannot  fail  to  be  objec- 
tionable. In  order,  therefore,  to  lessen  his  discomfort  as 
much  as  possible,  we  should  try  to  devise  appliances  that 


PRELIMINARIES.  85 

will  occupy  110  more  space  than  is  necessary  and  also  have 
them  free  from  all  rough  projections.  Very  little  is  required 
to  cause  abrasion  of  or  injury  to  the  soft  tissues  of  the  oral 
cavity,  and  when  once  caused  such  lesions  are  the  source  of 
much  pain. 

Least  Interference  with  Speech  and  Mastication. — Most  patients 
apply  to  us  for  correction  of  irregularity  at  a  time  when  their 
education  is  in  progress.  Their  lessons  must  be  recited,  and 
their  enunciation  must  be  distinct  enough  to  be  understood 
by  the  teacher.  With  a  large  and  cumbersome  appliance  in 
the  mouth  it  would  prove  very  difficult  for  them  to  speak 
distinctly,  and  they  would  thus  be  placed  at  a  disadvantage. 

They  are  also  in  their  growing  age  when  the  body  needs 
an  abundance  of  nutritious  food  to  supply  the  demands  of 
the  various  tissues.  If  mastication  be  insufficient  through 
imperfect  occlusion  or  through  tenderness  of  the  teeth  caused 
by  a  bulky  fixture,  nutrition  will  be  inadequate  to  the  needs 
of  the  system. 

Such  conditions  can  and  ought  to  be  avoided  by  a 
properly  constructed  appliance. 

Cleanliness. — The  cleanliness  of  any  appliance  will  depend 
both  upon  its  character  and  method  of  construction  and  the 
care  that  is  given  to  it.  In  all  cases  the  patient  should  be 
instructed  by  the  operator  in  the  proper  method  of  using  the 
tooth-brush  and  of  rinsing  the  mouth.  This  can  best  be 
done  by  an  ocular  demonstration  in  the  office  by  the  opera- 
tor brushing  his  own  teeth,  and  then  taking  a  quantity  of 
water  in  his  mouth  and  using  the  lips  and  cheeks  bellows- 
fashion  forcing  it  into  every  interdental  space.  The  patient 
should  be  instructed  to  follow  these  methods  of  cleansing 
each  time  after  eating  as  well  as  before  retiring  and  after 
rising. 

As  even  with  all  of  this  care  the  teeth  of  the  patient  will 
not  be  kept  as  clean  as  we  should  like  it  is  well  to  supple- 
ment his  efforts  by  a  thorough  spraying  of  the  mouth  with 
a  mild  antiseptic  preparation  upon  the  occasion  of  each 


86  ORTHODONTIA. 

visit.  A  Davidson  spray  bottle  with  fine  aperture  and  operated 
by  compressed  air  is  probably  the  most  efficient  as  well  as  the 
most  rapid  means  of  flushing  the  mouth  and  cleansing  both 
teeth  and  appliances. 

Inconspicuousness. — Annoyance  from  wearing  a  conspicu- 
ous appliance  is  often  added  to  the  other  ills  which  the 
patient  is  subjected  to  during  the  process  of  regulation.  An 
appliance  of  this  character,  while  often  producing  distortion 
of  the  lips,  also  attracts  much  attention  and  compels  the 
wearer  to  make  frequent  answers  to  the  same  oft-repeated 
question. 

Young  persons  attending  school  or  entering  society  are 
naturally  very  sensitive  to  the  ill-appearance  of  any  con- 
spicuous device.  Whenever  the  same  result  can  be  accom- 
plished by  a  concealed  fixture  as  by  an  exposed  one,  it  is 
better  to  adopt  the  former ;  but  where  a  better  or  more  sat- 
isfactory result  can  be  obtained  by  the  use  of  a  more  promi- 
nent fixture,  appearance  will  have  to  be  subordinated  to 
utility. 

Stability. — The  quality  of  stability  has  previously  been 
spoken  of,  but  its  real  practical  importance  cannot  be  too 
strongly  insisted  upon.  It  is  a  sine  qua  non  in  orthodontic 
practice.  With  it,  we  have  a  reasonable  certainty  of  results ; 
without  it,  all  is  uncertainty. 

Should  an  appliance  shift  its  position  or  become  loose  at 
one  or  more  of  its  anchorages  either  no  force  will  be  exerted 
or  it  will  be  directed  in  a  wrong  manner. 

Serious  harm  has  often  resulted  from  instability. 

In  some  cases,  as  where  most  or  all  of  the  upper  teeth 
are  to  be  drawn  backward,  we  -have  apparently  no  point  for 
proper  anchorage.  Stability  or  fixedness  of  position  for  an 
appliance,  in  such  cases,  not  being  obtainable  within  the 
mouth,  some  fixture  must  be  devised  which  will  have  its 
point  of  resistance  outside,  as  on  the  back  of  the  head. 

The  invention  of  the  head-cap  for  this  purpose  was  a 
notable  addition  to  our  armamentarium,  and  at  once  solved 
what  had  been  a  most  difficult  problem. 


CHAPTER  II. 

MATERIALS  AND  CONSTRUCTION  OF  APPLIANCES. 

Before  taking  up  the  construction  of  appliances  it  will  be 
necessary  to  consider  the  different  materials  at  our  disposal 
in  order  that  we  may  select  from  them  those  best  suited  to 
our  purpose. 

Gold. — Gold,  in  its  non-elastic  condition,  has  been  and 
probably  always  will  be  one  of  the  most  useful  of  the  metals 
for  the  construction  of  parts  of  regulating  appliances.  Its 
softness,  adaptability  and  strength  are  all  qualities  of  the 
greatest  value  and  render  it  serviceable  in  numberless  ways. 
To  preserve  its  purity,  and  as  far  as  possible  to  prevent  oxi- 
dation, it  should  never  be  used  of  a  carat  less  than  20  or  22. 

Platinous  Gold. — Gold  in  a  pure  state,  or  alloyed  with 
silver  or  copper,  does  not  possess  the  stiffness  necessary  for 
its  use  in  the  form  of  bars,  springs  or  accesories,  where  great 
resistance  or  elasticity  is  requisite,  but  when  alloyed  with 
about  five  per  cent,  of  platinum  it  attains  a  degree  of  elas- 
ticity second  only  to  steel.  In  this  form  it  is  one  of  our 
most  useful  materials,  for  even  the  heat  of  soldering  does 
not  rob  it  of  its  elastic  quality. 

This  alloy  of  gold  can  be  purchased  in  the  dental  depots 
in  plate  of  any  thickness  and  in  wire  of  any  form  or  size. 
When  used  for  the  construction  of  screws  or  supports,  its 
stiffness  is  the  property  taken  advantage  of,  while  in  the 
form  of  levers  or  bows  its  elasticity  constitutes  its  chief 
excellence. 

Platinized  Gold. — This  is  not  an  alloy  but  a  combination 
made  by  uniting  under  pressure  a  thin  sheet  of  pure  gold 
with  another  of  pure  platinum.  Once  brought  "  within  the 
sphere  of  cohesive  attraction,"  usually  by  being  passed 

87 


88  ORTHODONTIA. 

through  the  rolls  of  a  mill,  neither  further  rolling  nor  heat 
will  again  separate  them.  As  both  metals  are  soft  the  com- 
bination is  correspondingly  pliable.  Having  gold  on  one 
side  and  platinum  on  the  other,  either  metal  can  be  made 
the  outside  one,  according  to  choice,  in  the  construction  of 
bands.  The  combined  metals  have  a  higher  fusing  point 
than  gold  alone,  and  some  regard  this  as  an  element  of 
security  in  soldering. 

Platinum. — Platinum,  on  account  of  its  tastelessness,  its 
non-oxidability  and  its  harmonious  color,  should  constitute 
it  one  of  the  best  metals  for  use  in  the  mouth.  Its  extreme 
pliability  and  softness,  however,  greatly  limit  its  usefulness, 
so  that  it  can  be  used  only  where  these  latter  qualities  do 
not  interfere  with  its  employment. 

It  is  used  in  the  construction  of  bands  that  are  to  be 
cemented  to  the  teeth  to  serve  as  anchorages  for  appliances 
but  more  particularly  in  those  which  are  to  form  parts  of 
retaining  fixtures. 

In  combination  with  other  metals,  in  the  form  of  alloys, 
however,  its  greatest  usefulness  is  developed. 

Iridio-Platinum. — This  alloy,  combining  the  color  and 
purity  of  platinum  with  the  hardness  and  stiffness  of 
iridium,  is  useful  for  bands,  bars  and  wires  in  connection 
with  regulating  appliances  where  platinum  alone  would  not 
be  available  on  account  of  its  softness. 

It  can  be  hard-soldered  without  losing  its  elasticity. 

Platinous  Silver. — This  alloy,  though  long  and  favorably 
known  in  England,  has  never  been  extensively  used  in 
America.  It  is  prepared  for  the  market  in  the  form  of  plate 
and  wire  of  every  gauge.  In  the  form  of  plate  it  is  largely 
used  abroad  as  a  base  for  artificial  dentures,  especially  small 
partial  pieces,  while  the  wire  is  used  as  a  support  for  the 
Ash  tube-teeth  and  other  purposes. 

The  alloy  is  composed  of  one  part  of  platinum  to  two  of 
silver.  Its  stiffness  and  elasticity  is  but  little  inferior  to 
platinous  gold,  while  its  cost  is  less  than  that  of  gold.  It 


MATERIALS    AND    CONSTRUCTION.  89 

can  be  rolled,  bent  or  fashioned  to  any  form  and  may  be 
soldered  with  the  highest  grades  of  gold  solder. 

In  the  form  of  wire  the  author  has  found  it  very  useful  in 
the  construction  of  bows  for  the  attachment  of  rubber  bands 
or  ligatures  to  draw  teeth  in  any  direction,  and  for  parts  of 
retaining  appliances  where  inconspicuousness  is  desirable. 
Its  non-oxidability  is  also  a  feature  of  considerable  value. 

Platinoid. — An  alloy,  under  this  name  has  been  placed 
upon  the  market  as  a  substitute  for  other  alloys  in  the  con- 
struction of  regulating  appliances.  It  may  be  had  in  all 
thicknesses  of  plate,  and  all  forms  of  wire.  It  is  inexpen- 
sive, almost  non-oxidable  and  very  elastic.  While  it  doubt- 
less serves  a  useful  purpose  in  some  departments  of  dentis- 
try it  is  of  little  value  in  orthodontia. 

German  Silver. — This  improperly  named  alloy,  composed 
of  copper,  zinc  and  nickel,  is  frequently  employed  in  the 
construction  of  regulating  appliances,  on  account  of  its 
stiffness  and  inexpensiveness.  While  it  may  be  regarded  as 
a  base  compound,  its  baseness  is  of  so  high  a  grade  that  it  does 
not  prove  objectionable  in  the  mouth.  Its  hardness  or  stiff- 
ness is  dependent  upon  the  proportion  of  nickel  it  contains. 
Soft  German  silver  contains  about  ten  per  cent,  of  nickel 
while  the  harder  varieties  often  contain  as  high  as  twenty- 
five  per  cent.  Drawing  also  increases  its  stiffness  and  elas- 
ticity, which  qualities,  however,  it  soon  loses  when  subjected 
to  the  heat  of  hard-.soldering.  The  lower  temperature  of 
soft-soldering  does  not  affect  it.  When,  therefore,  German 
silver  wire  is  to  be  employed  for  its  elastic  properties  as  in 
the  expansion  arch  or  for  hardness  or  toughness  as  in  the 
construction  of  screws  and  nuts  the  variety  known  to  the 
trade  as  "  twenty-five  per  cent,  nickel  "  should  be  obtained 
and  it  must  not  have  been  annealed  after  its  final  drawing. 
For  bands,  or  where  softness  and  pliability  are  desired  Ger- 
man-silver plate  of  the  "  ten  per  cent,  nickel "  is  to  be 
preferred,  and  it  should  be  well  annealed  before  using. 

So  generally  recognized  are  the  valuable  qualities  of  this 


90  ORTHODONTIA. 

alloy  that  it  has  come  into  very  general  use  almost  sup- 
planting other  alloys  and  metals  in  the  construction  of 
regulating  appliances. 

The  stock  fixtures  or  "  ready-to-wear  "  appliances  sold  by 
dental  supply  houses  are  all,  or  nearly  all,  made  from  this 
alloy. 

While  they  oxidize  readily  in  use,  even  when  electro- 
gilded,  appliances  may  be  kept  reasonably  bright  by  being 
gone  over  in  the  mouth  with  bristle-disks  and  pumice  at 
each  visit  of  the  patient. 

Steel. — This  metal  has  the  same  desirable  qualities  of  firm- 
ness and  elasticity  that  are  found  in  platinous  gold,  and 
possesses  them  in  a  higher  degree,  so  that  it  is  used  in  pref- 
erence to  the  former  metal  where  greater  power  is  needed. 

Used  either  to  produce  pressure  by  its  own  elasticity,  or  as 
a  medium  for  the  attachment  of  other  power-producing 
appliances,  it  has  been  one  of  the  most  commonly  employed 
materials  for  the  construction  of  regulating  appliances. 

There  are  two  disadvantages,  however,  connected  with  its 
use: — one  is,  that  it  cannot  be  highly  heated  (as  in  hard 
soldering)  without  destroying  its  temper;  and  the  other, 
that  it  oxidizes  so  readily  when  in  contact  with  the  fluids 
of  the  mouth. 

Compressed  Wood. — The  use  of  this  substance  is  very  old. 
Before  the  introduction  of  either  soft  or  vulcanized  rubber 
the  expansibility  of  compressed  wood  under  moisture  was 
employed  in  lieu  of  elasticity. 

The  author  occasionally  finds  great  advantage  from  its 
use  in  the  separation  of  teeth  for  the  accommodation  of 
some  malposed  tooth,  where  the  existing  space,  though  not 
sufficient,  is  still  too  great  to  admit  of  the  use  of  elastic  rubber. 

In  such  cases  it  is  his  custom  to  cut  a  cross-section  from 
some  compressible  wood,  such  as  cotton-wood,  a  little  larger 
than  the  space  it  is  to  occupy.  This  is  compressed  in  the 
direction  of  the  length  of  the  fibre  by  means  of  a  hammer, 
after  which  it  is  notched  at  each  end  to  fit  the  convex  sur- 


MATERIALS    AND    CONSTRUCTION. 


91 


faces  of  the  teeth  to  be  moved.  Upon  being  placed  in  posi- 
tion its  expansion  by  the  absorption  of  the  fluids  of  the 
mouth  quickly  causes  movement  of  the  teeth.  In  the  course 
of  its  expansion  it  adapts  itself  accurately  to  the  tooth 
surfaces  and  thus  does  not  become  dislodged  or  slip  from  its 
position.  See  Fig.  36. 

FIG.  36. 


Elastic  Rubber. — The  resilience  of  elastic  rubber  was  early 
recognized  as  a  valuable  property  that  might  be  used  to 
advantage  in  producing  traction  upon  teeth  to  be  moved. 
It  was  first  used  in  the  form  of  strips  attached  at  each  end 
by  ligature,  but  since  the  introduction  of  rubber  tubing, 
rings  or  bands  cut  from  the  same  have  been  employed 
instead.  Their  first  employment  has  been  credited  to 
Dr.  E.  G.  Tucker,  of  Boston,  about  the  year  1846. 

These  sections,  cut  from  the  smaller  sizes 
of  French  rubber  tubing,  are  now  in  almost 
universal  use  in  connection  with  other 
appliances  for  regulating,  and  their  value 
has  been  greatly  enhanced  since  the  Magill 
band  has  furnished  a  better  means  for 

4.1      •  i    ,  Sizes  of  Rubber  Tubing 

tneir  attachment.  most  generally  used. 


FIG.  37. 


92  ORTHODONTIA. 

Their  power,  though  great,  is  limited,  for  they  cannot 
exert  so  great  a  force  as  the  metals,  but  their  wide  range 
of  applicability  and  the  persistence  of  their  power  places 
them  among  the  most  valuable  adjuncts  of  regulating 
devices. 

In  use,  their  tendency  to  slip  off  the  tooth  or  up  under 
the  gum  (which  constitutes  the  chief  objection  to  their 
employment)  must  be  guarded  against  by  so  securing  them 
that  change  of  position  will  be  impossible.  They  should 
never  be  permitted  to  rest  upon  or  touch  the  soft  tissues  at 
any  point. 

Vulcanite. — Soon  after  the  introduction  of  vulcanite  as  a 
base  for  artificial  teeth,  its  qualities  of  adaptability,  strength 
and  elasticity  were  recognized  and  utilized  in  the  construc- 
tion of  appliances  for  regulating.  In  its  day  it  served  a 
useful  purpose,  but  for  very  many  years  it  has  been  largely 
discarded  because  other  materials  and  better  methods  of 
construction  have  superceded  it.  When  used  at  all  now  it 
is  employed  principally  in  the  construction  of  Coffin  plates, 
simple  bite-plates  and  retainers  after  lateral  expansion  of 
the  arch. 

Silk  Ligatures. — The  contraction  of  silk,  linen  or  cotton 
thread  in  contact  with  moisture,  enables  us  to  make  use  of 
it  where  the  gentlest  tractile  power  is  desired.  Most  fre- 
quently it  is  employed  simply  as  a  ligature  in  attaching 
some  appliance  to  the  teeth,  but  it  has  often  been  used  to 
advantage  in  cases  where  teeth  were  to  be  moved  slowly 
and  a  very  short  distance.  Employed  in  this  way  for 
the  moving  of  single-rooted  teeth,  its  gentle  power,  together 
with  its  safety  and  simplicity,  will  often  prove  the  very 
qualities  we  desire. 

China-Grass  Line — This  material  has  been  extensively 
used  for  ligatures  in  regulating,  being  preferred  for  that 
purpose  to  silk,  cotton  or  linen. 

It  is  the  Boehmeria  nivea  of  botanists,  and  more  commonly 
known  as  Ramie  or  Rhea  fibre,  and  is  the  material  from 


MATERIALS    AND    CONSTRUCTION.  93 

which  China-grass  cloths  are  manufactured.  It  is  stiff' 
enough  to  be  threaded  with  a  pair  of  tweezers  between  the 
teeth  at  their  necks,  thus  avoiding  the  pain  of  forcing  a 
ligature  between  them  when  tender. 

It  is  non-elastic,  but  shrinks  greatly  without,  softening 
when  moist,  thus  exerting  considerable  traction  without 
producing  pain.  It  comes  in  the  form  offish-lines. 


CONSTRUCTION  OF  APPLIANCES. 

TOOLS. 

As  a  preliminary  to  the  act  of  construction  the  practi- 
tioner is  supposed  to  have  in  his  laboratory  outfit  such  com- 
monly used  tools  as  : — 

Mouth  blowpipe. 

Plate  shears. 

Flat  nose  pliers. 

Round  nose  pliers. 

Jewelers'  saw. 

Anvil. 

Riveting  hammer. 

Files. 

Solder  tweezers. 

Small  Bunsen  gas  burner. 

In  addition  to  these  he  should  obtain  the  following  : — 

Brown  &  Sharpe  wire  gauge. 

Double  end  calipers  for  inside  and  outside  measurement. 

Draw  plate  (Joubert.) 

Draw  pliers  or  tongs. 

A  micrometer  gauge,  although  expensive,  is  a  very  desir- 
able and  useful  tool  for  the  accurate  gauging  of  plate  and 
wire  in  thousands  of  an  inch.  These  fine  tools  are  shown 
in  Fig.  38.  Other  important  and  necessary  tools  are  shown 
in  Fig.  39. 

No.  1  is  a  Herbst  cutting  pliers  or  nippers.  In  addition 
to  the  front  cutting  edges,  the  jaws  between  these  edges  and 


94 


ORTHODONTIA 


the  joint  are  flattened   and  serve  the  purpose  of  ordinary 
pliers  for  straightening  bent  wire  or  plate. 

No.  2  is  an  S.  S.  W.  wire  cutter.  It  is  especially  useful  in 
cutting  heavy  wire  of  all  kinds  and  the  only  tool  that  will 
cut  piano  wire  satisfactorily. 

FIG.  38. 


No.  3  is  a  small  hand  vise  having  pivoted  jaws  operated 
by  a  tapering  mandrel,  which  forms  a  part  of  the  revolving 
handle.  The  latter  is  center-bored  to  accommodate  wire  of 
any  length. 

No.  4  is  a  jewelers'  pin-vise  with  four-part  jaws.  It  is 
tightened  by  means  of  the  knob  on  end  of  handle  and  is 
also  center-bored.  It  is  most  useful  for  holding  wire  while 
soldering  the  same  to  bands  for  attachments  of  various  kinds. 


MATERIALS    AND    CONSTRUCTION. 


95 


No.  5  is  a  small  asbestos  soldering  block.  It  is  made 
from  strips  of  asbestos  paper,  two  inches  wide,  rolled  over  a 
wire  until  it  acquires  a  diameter  of  one  and  three-quarter 
inches.  The  edge  of  the  final  lap  is  fastened  with  liquid 

glue. 

FIG.  39. 


3.  4. 


It  is  a  most  valuable  adjunct  to  the  soldering  outfit, 
because  the  layers  slide  upon  one  another  under  pressure  of 
the  thumb  at  either  end,  and  its  form  can  thus  be  altered 
at  will.  Ordinary  pins  or  pointed  wires  enter  it  readily  at 
any  place  for  holding  work  in  place. 

Fig.  40  represents  four  valuable  forms  of  tweezers  for 
holding  attachments  or  parts  in  soldering. 

No.  1  is  a  double  end,  socketed  nut  wrench,  placed  on  this 
plate  simply  for  convenience  of  illustration. 

No.  2  is  a  tweezers  with  delicate  points  bent  at  an  angle 
and  a  small  slide-ring  for  holding  work  automatically.  For 
soldering  pipes  or  tubes  to  a  band  one  point  or  jaw  is  placed 
inside  the  tube  and  the  other  inside  the  band,  the  slide- 
ring  keeping  them  firmly  in  position  while  being  united. 


96 


ORTHODONTIA. 


FIG.   40. 


No.  3  is  a  straight,  flat  nose  tweezers  with  slide  attach- 
ment, most  useful  for  holding  band  and  tube  when  these 
are  parallel  to  one  another. 

No.  4  is  a  very  delicate  tweezers  with   long,  fine  points, 

bent  at  an  angle  and 
provided  with  a  slide- 
ring.  The  fine  points 
prevent  drawing  the 
heat  from  the  parts 
while  being  soldered, 
and  their  long  angle 
enables  one  to  hold 
the  work  in  very 
favorable  positions. 

No.  5  is  the  Angle 
soldering  tweezers, 
with  the  points  bent 
at  right  angles  to 
one  another.  They 
are  very  useful  in 
soldering  the  lap  of 
bands  or  two  bands 
together  and  other 
delicate  work. 

Fig.  41  represents  the  author's  set  of  screw-cutting  tools, 

consisting 
of  an  adjust- 
able die  and 
die-  holder 
for  cutting 
threads  on 


5. 


FIG.  41. 


Guilford  Taps  and  Die. 


wre 


taps  for  threading  nuts.     They  cut  a  clean,  sharp,  coarse 
thread,  gauge  .050  of  an  inch. 


MATERIALS   AND    CONSTRUCTION'.  97 

PREPARATION  OF   MATERIAL. 

Wire  Drawing. — Wire  may  readily  be  drawn  down  from 
a  larger  to  a  smaller  gauge  by  means  of  the  draw-plate  and 
draw-tongs  ( See  Fig.  38 ).  Before  using  the  draw-plate  the 
holes  should  be  filled  with  melted  bees-wax  or  equal  parts 
of  bees-wax  and  tallow  to  act  as  a  lubricant.  It  is  then 
clamped  firmly  in  the  bench-vise.  The  wire  after  being 
annealed  should  be  reduced  at  one  end  by  filing  or  ham- 
mering and  the  pointed  end  passed  through  the  hole  in  the 
draw-plate  next  less  in  diameter  than  the  wire  itself.  It  is 
then  grasped  by  the  tongs  or  pliers  and  drawn  through 
with  a  continuous  and  steady  pull.  In  similar  manner  it 
is  drawn  through  the  successively  smaller  holes  until  the 
desired  gauge  is  obtained.  After  each  two  or  three  draw- 
ings the  wire  should  be  annealed. 

Steel  wire  cannot  be  drawn  by  ordinary  methods  on 
account  of  its  hardness,  but  it  can  be  bought  in  all  sizes. 

Round  Tubing. — The  drawing  of  tubing  is  as  simple  a 
process  as  that  of  drawing  wire,  and  is  done  in  much  the 
same  way.  From  a  piece  of  German  silver  plate,  No.  27, 
cut  a  strip  of  desired  length  and  of  a  width  equal  to  three 
and  a  third  times  the  outside  diameter  of  the  proposed  tub- 
ing. Shape  one  end  of  the  strip  like  the  nib  of  a  pen  and 
curve  or  round  the  entire  piece  somewhat  by  forcing  it  into 
a  groove  cut  in  a  block  of  hard  wood,  using  a  piece  of  wire 
and  hammer  for  the  purpose.  The  pointed  end  is  then 
passed  into  one  of  the  larger  holes  of  the  draw-plate,  seized 
with  the  pliers  and  drawn  through.  This  operation  is 
repeated  through  the  holes  next  in  size  until  the  cut  edges 
of  the  strip  are  in  close  apposition.  If  it  be  desired  to 
reduce  the  external  diameter  after  the  tube  is  formed,  it  can 
be  done  by  simply  continuing  the  process.  As  the  drawing 
stiffens  the  metal  it  will  be  necessary  to  anneal  it  occasion- 
ally during  the  process.  Where  the  tubing  is  to  be  used  in 
considerable  lengths  without  soldering  and  great  stiffness 


98  ORTHODONTIA. 

is  required,  as  in  the  encasement  for  jack-screws,  there 
should  be  no  annealing  of  the  metal  near  the  close  of  the 
operation  of  drawing. 

The  joint  of  this  tubing  can  be  closed  by  soldering  with 
silver  solder,  but  in  doing  so  great  care  must  be  exercised 
to  avoid  having  the  solder  run  into  the  inside  of  the  tube. 

Square  Tubing.  —  Tubing  of  this  form  can  be  made  from 
round  tubing.  It  should  be  drawn  round  to  near  the 
desired  size  in  the  ordinary  draw-plate,  after  which  the  last 
four  or  five  drawings  must  be  made  through  a  special 
square-hole  draw-plate. 

As,  however,  this  form  of  tubing  needs  to  have  thick 

walls  for  the  construction  of 
'  nuts,  it  had  better  be  bought 


from  the  manufacturer,  who 


Square  Tubing.  makeg  ^  jn  ^  form  Qf 

and  then  drills  the  central  hole.     (See  Fig.  42.) 

Oval  Tubing.  —  Oval  or  elliptical  tubing  is  easily  made 
from  round  tubing  by  flattening  it  slightly  between  the 
jaws  of  a  vise,  or  preferably  by  passing  it  once  or  twice 
between  the  rolls  of  a  rolling  mill.  In  all  cases  it  is  made 
from  closed  or  seamless  tubing. 

Screws.  —  The  wire  that  is  to  be  threaded  or  screw-cut 
should  be  smoothly  drawn  and  of  moderate  temper.  It 
should  be  of  exactly  the  same  diameter  as  the  hole  in  the 
die  would  be  if  the  threads  were  removed.  If  smaller  than 
this,  a  full,  deep  thread  will  not  be  cut,  and  if  larger,  the 
wire  will  be  liable  to  be  twisted  off  in  the  attempt.  In  cut- 
ting the  thread,  the  wire  should  be  slightly  tapered  at  its 
end  and  grasped  in  the  bench-vise,  horizontally  or  vertically, 
with  only  about  half  an  inch  of  its  length  protruding.  To 
avoid  marring  the  wire,  the  jaws  of  the  vise  should  be  pro- 
vided with  lead  or  brass  caps. 

The  die  (in  holder,  see  Fig.  41)  should  now  be  held 
against  the  end  of  the  wire  at  right  angles  to  it  and  given  a 
quarter  or  half  turn  with  firm  pressure.  This  should  be 


MATERIALS    AND    CONSTRUCTION.  99 

repeated  four  or  five  times  until  the  tool  is  well  started  in 
its  work,  care  being  taken  to  preserve  the  forward  pressure 
and  to  see  that  the  die  is  kept  at'  a  right  angle  to  the  wire. 
The  operation  may  now  proceed  more  rapidly  until  all  of 
the  exposed  portion  of  the  wire  has  been  covered. 

If  a  longer  portion  is  to  be  threaded,  more  of  the  wire  may 
now  be  exposed  and  the  operation  continued.  A  little  oil 
fed  to  the  tool  will  greatly  facilitate  the  cutting.  In  revers- 
ing the  operation  to  release  the  tool  care  should  be  exercised 
not  to  mar  the  thread. 

j^uts. — For  use  in  regulating  appliances,  nuts  should  be 
square,  about  No.  13  in  diameter,  and  not  less  than  J  of 

an  inch  in  length  in  order 

i,  j    v  ij  FlG-  43- 

to   have    a    good   hold   and 


resist    the   necessary    strain. 

When    greater    strain    than . 

fo^^m-J^mml^^^^^^^^&i^jm 

ordinary  is  to  be  withstood,  * 

they     Should     be     longer,     to  Brag-Screws  (Angle). 

prevent  stripping  of  the  thread.  They  are  made  from 
heavy,  square  German  silver  tubing,  by  sawing  it  into 
sections,  grasping  these  in  a  hand-vise  and  then  drilling 
and  tapping  them. 

In  using  the  tap  to  cut  the  threads  on  the  inside  of  these 
nuts,  it  should  be  oiled,  held  in  the  hand-vise  (Fig.  39,  No.  3) 
and  fed  carefully  with  an  alternate  forward  and  backward 
movement  to  avoid  clogging  and  danger  of  breaking  the 
highly  tempered  tool. 

/  Hard-Soldering. — Both  the  student  and  practitioner  are 
supposed  to  be  familiar  with  this  process,  so  that  few  sug- 
gestions will  be  needed. 

Parts  of  German  silver  appliances  should  be  soldered  with 
silver  solder  (silver  2,  brass  1)  while  any  of  the  compounds 
of  gold  or  platinum  may  be  united  with  either  silver  or 
gold  solder.  The  latter  when  used  should  not  be  less  than 
18  karats  fine  to  keep  its  color  in  the  mouth.  In  joining 
articles  with  hard  solder  the  parts  to  be  united  should  be 


100  ORTHODONTIA. 

touched  with  the  least  quantity  of  liquified  borax  and  only 
as  much  solder  applied  as  is  necessary. 

After  drying  with  moderate  heat,  the  full  flame  should 
be  directed  upon  the  parts  to  be  united  and  fusion  accom- 
plished as  quickly  as  possible.  Most  of  the  hard-soldering 
required  in  constructing  portions  of  regulating  appliances 
may  be  done  by  holding  the  parts  in  the  flame  of  a  small 
Bunsen  burner  or  alcohol  annealing  lamp.  In  other  cases 
a  larger  flame  with  a  blow-pipe  to  direct  and  concentrate  it 
will  be  necessary,  the  parts  being  laid  or  secured  in  position 
upon  the  asbestos  soldering  block.  (Fig.  39,  No.  5.) 

When  two  solderings  are  necessary  for  the  same  piece, 
the  first  joint  may  be  kept  from  unsoldering  during  the 
second  process  by  placing  an  extra  wire  clip  upon  it  or  by 
seizing  it  with  the  tweezers  at  that  point  and  thus  protecting 
it  from  over-heating. 

Soft-Soldering. — In  uniting  small  parts  of  appliances  by 
means  of  soft-solder,  they  may  be  held  in  the  tweezers 
(Fig.  40),  or  the  spring  clips  (Plate  A,  Nos.  34,  35,  36,  37), 
or  wrapped  with  binding  wire.  After  applying  the  solder- 
ing fluid,  the  piece  is  held  over  an  annealing  lamp  and 
when  sufficiently  heated  is  touched  with  the  end  of  a  thin 
rod  of  solder,  which  at  once  melts  and  unites  the  parts.  In 
this  way  the  minimum  amount  of  solder  may  be  applied. 

For  soldering  larger  parts  of  appliances,  as  in  forming  the 
Jackson  cribs  and  springs,  they  should  be  secured  in  proper 
position  on  the  plaster  model,  and  after  applying  the  fluid 
and  laying  a  piece  of  solder  on  the  parts,  the  latter  is  melted 
and  the  parts  joined  with  a  soldering  iron  previously  heated 
over  a  Bunsen  burner. 

Wire  Bending. — Wire  may  be  bent  into  any  form  by  means 
of  the  various  pliers,  assisted  at  times  by  the  bench-  or  hand- 
vise.  Any  curve  can  be  given  to  it  with  the  round-nose 
pliers  or  the  clasp  bender,  while  for  bending  it  at  a  right  or 
acute  angle,  it  should  be  held  in  the  vise  or  pliers  close  to 
the  bending  point  and  the  free  end  grasped  and  bent  over 


MATERIALS    AND    CONSTRUCTION.  101 

with  the  flat-nose  pliers.  If  the  wire  be  of  large  size  it  may 
best  be  bent  at  a  right  angle  by  grasping  it  in  the  bench- 
vise  and  forcing  the  free  end  down  with  a  hammer. 

When  piano  wire  needs  a  sharp  bend  it  should  always  be 
done  in  this  latter  manner.  For  bending  piano  wire  into  a 
short  curve,  as  for  making  or  altering  the  form  of  the  Coffin 
W-spring,  the  clasp-benders  should  be  used,  on  account  of 
their  convenience  and  superior  power. 

Soldering  Clips. — These  useful  little  adjuncts  are  fashioned 
from  piano  wire  No.  18  by  means  of  round-  and  flat-nose 
pliers.  They  are  serviceable  in  holding  together  small 
parts,  such  as  bands  to  bands  or  tubing  to  bands  during 
either  hard  or  soft-soldering.  They  lose  some  of  their 
temper  through  successive  heatings,  but  will  long  remain 
serviceable.  They  should  be  about  an  inch  in  length  and 
are  shown  at  bottom  of  Plate  A. 

CONSTRUCTION. 

Bands. — Bands  for  encircling  teeth  and  serving  as  means 
of  attachment  for  operating  or  retaining  appliances  may  be 
made  from  gold  plate  (18  to  22  karats  fine),  platinous  gold, 
iridio-platinum,  or  German  silver.  All  of  those  mentioned, 
except  the  last,  will  remain  nearly  free  from  oxidation  in 
the  mouth.  German  silver  is  now  most  commonly  used, 
for  when  complete  with  necessary  attachments  it  is  easily 
gilded.  As  a  rule,  bands  should  be  made  to  fit  closely,  so 
as  to  afford  slight  space  for  the  cement  which  is  to  hold 
them  in  position,  and  where  practicable,  the  tooth  to  be 
fitted  should  be  freed  from  contact  with  its  neighbors  by 
previous  wedging.  As  this  cannot  always  be  done,  the 
bands  in  some  cases  will  have  to  be  forced  over  the  teeth  in 
spite  of  their  contact.  In  such  event  they  should  be  con- 
structed from  the  stiffest  and  least  yielding  of  the  metals 
mentioned,  such  as  platinous  gold,  or  iridio-platinum. 
Bands  made  from  these  metals,  even  though  thin,  will 
retain  their  form  without  "  buckling "  while  being  forced 


102  ORTHODONTIA. 

into  place.  Where  the  teeth  to  be  banded  are  not  in  close 
contact,  any  of  the  other  metals  will  serve  as  well  for  the 
construction  of  bands.  The  band  material  should  not 
exceed  No.  36  in  thickness  and  be  cut  into  strips  from  -£% 
to  •/-%  of  an  inch  in  width. 

For  the  six  anterior  teeth  the  strips  should  be  curved  so 
that  when  bent  to  encircle  the  tooth  with  the  convex  edge 
toward  the  gum  on  the  labial  side  the  ends  will  overlap 
on  the  lingual  surface  in  a  nearly  horizontal  line. 

For  molars  and  bicuspids  the  band  should  be  straight, 
and  if  desired,  may  be  contoured  with  the  contouring  pliers. 

Ferrules  are  strongest  when  made  with  a  lap  joint,  and 
their  ends  may  be  held  in  close  apposition  by  passing  bind- 
ing wire  around  them  and  twisting  the  ends  to  serve  as  a 
holder  while  soldering  in  the  flame  of  a  lamp,  or  the  lapped 
ends  may  be  held  with  a  wire  clip.  (Plate  A,  Fig.  36.) 

Another  plan  of  construction,  preferred  by  many,  is  to 
pass  the  thin  band  material  around  the  tooth  with  the  ends 
projecting  on  the  labial  or  buccal  side.  These  ends  are  then 
grasped  with  flat-nose  pliers  and  drawn  tight.  Removed 
from  the  tooth  the  joint  is  held  close  with  tweezers  and  sol- 
dered, after  which  the  surplus  material  is  cut  off  and  ground 
smooth. 

In  some  cases,  as  in  partly  erupted  cuspids  and  deciduous 
molars,  where  the  exposed  portion  of  the  crown  is  short  and 
conical,  it  is  better  to  have  a  cap  entirely  covering  the  crown 
so  as  to  gain  a  firmer  hold. 

This  is  easily  made  by  reproducing  the  crown  in  Melotte's 
metal,  and  after  roughly  adapting  the  cap  to  the  natural 
tooth  or  its  duplicate  in  plaster,  completing  the  operation 
by  swaging  it  between  a  die  and  counter. 

Dr.  Matteson's  method  of  doing  this  is  well  shown  in 
Fig.  44. 

For  a  partly  erupted  cuspid  he  takes  a  circular  piece  of 
plate,  and  after  cutting  from  it  a  segment,  as  in  (6),  bends  it 
into  the  form  of  a  cone  and  solders  the  edges.  It  is  then 


MATERIALS    AND    CONSTRUCTION. 


FIG.   44 


swaged  to  form  between  a  die  and  counter.  For  a  deciduous 
molar  he  cuts  the  plate  into  the  form  of  a  cross  (d),  folds  the 
arms  down,  then  swages  and  solders.  In  some  cases,  for 
more  secure  anchorage,  he  forms  a  group  of  caps  (/)  by 
soldering  several  together. 

The  attachments  that  bands  are  most  commonly  supplied 
with  are  headed  pins, 
wire  hooks  and  pieces 
of  metal  tubing. 
Tubes  are  held  in 
position  upon  bands 
for  soldering  by 
means  of  wire  clips, 
or  they  may  be  held 
by  means  of  a  point- 
ed instrument  passed 

through  the  tube.  Matteson  Caps. 

As  tubes  are  usually  not  soldered  along  their  edges  after 
being  drawn,  the}7  can  be  closed  at  the  time  of  soldering  to 
the  bands  by  placing  the  joint  next  to  the  band,  and  when 
desired  to  be  left  open  the  joint  is  turned  away  so  as  not  to 
be  included  in  the  soldering. 

Headed  pins  may  be  obtained  from  a  vulcanite  tooth,  and 
after  being  filed  to  a  point  can  be  inserted  into  a  hole 
drilled  in  the  band. 

When  a  band  is  to  be  supplied  with  hooks  on  opposite 
sides,  a  convenient  way  of 
attaching  them  is  to  drill  a 
hole  in  each  side  of  the  band 
and  pass  entirely  through 
them  a  wire  bent  into  a  hook 
at  one  end.  After  soldering, 
the  straight  end  is  also  bent 


o 


Bands  with  Hooks. 


and  the    wire  cut   from  the 

centre  of  the  band.     A  hook  for  one  side  only  may  be  made 

by  bending  a  wire  at  right  angles  and  inserting  its  longer 


104  ORTHODONTIA. 

end  into  the  hole  in  the  band.  After  soldering,  the  inner 
portion  is  cut  off  with  a  fissure  bur ;  or  a  long  wire,  serving 
as  a  handle,  may  have  its  end  tapered,  inserted  into  the  hole 
in  the  band  and  soldered  over  a  lamp ;  after  which  it  is  cut 
to  proper  length,  and  the  end  bent  into  the  form  of  a  hook, 
as  in  Fig.  45. 

A  simpler  and  more  convenient  method  of  soldering  the 
end  of  a  wire  to  a  band  is  to  flow  a  little  silver  solder  on  the 
band  at  the  point  where  the  wire  is  to  be  attached.  Then 
placing  the  wire  in  the  small  pin-vise  (Fig.  39,  No.  4)  and 
grasping  the  band  at  some  point  with  the  tweezers  (Fig.  40, 
No.  3),  the  two  are  held  in  contact  over  the  flame  until  the 
solder  is  fused.  To  avoid  displacement,  blow  the  flame 
away  from  the  part  until  the  solder  is  chilled,  but  do  not 
move  the  hands. 

Joining  Tubing. — When  two  pieces  of  tubing  are  to  be 
joined  end  to  end,  the  ends  should  be  properly  squared  and 
the  bur  removed.  They  can  then  be  laid  in  position  on  the 
asbestos  block  and  held  with  bent  pins  while  being  sol- 
dered. Very  little  borax  and  solder  should  be  used  to  avoid 
its  running  into  the  tube.  (Plate  A,  Fig.  33.)  When  it  is 
desired  to  join  them  at  a  right  or  an  obtuse  angle  the  end 
of  one  piece  will  have  to  be  shaped  and  filed  concave  to  fit 
the  convex  surface  of  the  other. 

Joining  Wire. — Two  pieces  of  wire  may  be  joined  end  to 
end  or  at  any  angle  in  the  same  manner  as  tubing,  or  two 
pieces  of  different  gauge  may  be  united  by  placing  them  in 
proper  position  and  securing  them.  (Plate  A,  Figs.  29,  30.) 

Stock  Material. — For  the  busy  practitioner  who  desires  to 
have  on  hand  the  simpler  parts  of  regulating  material,  such 
as  seamless  German  silver  bands,  threaded  wire,  threaded 
nuts,  plain  nuts  (drilled  but  not  tapped),  round  and  square 
wire,  round  and  square  tubing,  sheet  metal,  etc.,  the  author 
suggests  that  they  may  be  obtained  from  either  of  two  manu- 
facturers : — Geo.  P.  Pilling  &  Son,  Twenty-third  and  Arch 
Streets,  Philadelphia,  and  the  Blue  Island  Specialty  Co.,  Blue 


MATERIALS    AND    CONSTRUCTION 


105 


Island,  Illinois.  In  addition,  Pilling  &  Son  manufacture  the 
author's  forms  of  taps  and  dies  illustrated  in  Fig.  41,  and 
the  Blue  Island  Co.  manufacture  the  seamless  bands  shown 
herewith. 

FIG.  46 


German  Silver  Bands  (seamless  drawn). 


These  bands  are  sections  cut  from  tubing  drawn  in 
cartridge  form  and  are  therefore  absolutely  seamless. 

They  may  be  had  either  annealed  or  unannealed  of 
twenty  different  diameters  and  of  30,  36  or  40  gauge. 

The  author  uses  principally  the  36  gauge.  It  is  his 
custom  to  select  an  unannealed  band  of  proper  size  and  force 
it  over  the  tooth  to  be  banded.  Being  thin  and  stiff  it  can 
be  forced  to  place,  no  matter  how  tightly  the  teeth  are  in 
contact.  It  causes  no  pain  or  inconvenience,  and  when  the 
patient*  returns  there  will  be  found  ample  room  for  the 
placing  of  a  similar  band,  to  which  the  desired  attachments 
have  in  the  meanwhile  been  made.  Any  number  of  teeth 
can  thus  be  banded  and  separated  in  a  way  much  superior 
to  the  common  method  of  using  rubber  or  waxed  tape. 


CHAPTER   III. 

STOCK  APPLIANCES  AND  SPECIAL  METHODS. 

Early  in  the  era  of  modern  regulation  the  idea  was  con- 
ceived of  having  special  regulating  appliances  devised, 
constructed  and  placed  upon  the  market  for  sale. 

A  two-fold  purpose  was  had  in  view : 

1.  To  furnish  practitioners  with  appliances  or   parts  of 
the  same  which  many  would  not  have  the  ability  to  con- 
struct themselves,  or  which  they  preferred  to  buy. 

2.  To  have  these  appliances  accurately  made  by  skilled 
artificers  and  suitable  machinery,  and  to  have  them  stand- 
ardized so  that  any  two   or   more  similar   parts   would   be 
exactly  alike  and  interchangeable. 

Probably  the  first  effort  in  this  direction  was  made  by 
Farrar  in  1876.  His  appliances  were  beautifully  con- 
structed and  for  a  time  had  a  ready  sale,  but  their  elabo- 
rateness and  complexity  caused  them  to  be  superseded  by 
others  of  simpler  form  and  different  construction. 

Dr.  Patrick  followed  with  a  set  of  devices  intended  to 
serve  the  purpose  in  all  the  simpler  forms  of  regulating, 
but  these  in  turn  fell  into  disuse. 

In  1887  Dr.  Angle  devised  a  method  of  regulating,  and  his 
appliances  were  placed  upon  the  market.  They  met  with 
such  favor  that  with  modifications  and  additions  they  have 
increased  in  popularity  and  are  to-day  more  generally  used 
than  any  other  "  ready  to  wear"  appliances. 

Fig.  47  shows  his  original  set  in  its  simplest  form. 

"A  "  is  a  large  traction  screw  encased  in  its  accompany- 
ing tube,  and  used  for  pulling  where  the  resistance  is  great. 
"  B "  is  a  smaller  traction  screw,  used  in  the  same  way 
where  the  resistance  is  slight,  or  where  from  any  reason  a 
delicate  "appliance  is  desired.  "C"  and  "D"  are  tubes 

106 


APPLIANCES    AND    METHODS. 


107 


which  are  soldered  to  bands  placed  upon  the  teeth  to  be 
moved,  into  which  the  ends  of  'the  traction  screws  are 
hooked.  "J"  is  a  jack-screw,  used  for  pushing,  the  end  of 
which  is  beaten  flat.  "  E  "  is  an  extra  piece  of  tubing,  by 
means  of  which  a  longer  jack-screw  can  be  made.  ."F" 
and  "  H  "  are  coils  of  band  material  of  different  thicknesses. 

FIG.  47. 


Angle's  Appliances. 

"  G"  is  a  wire  used  in  retaining  the  teeth  and  also  to  assist 
in  securing  anchorage  in  some  cases,  and  "  RR  "  are  small 
retaining  tubes,  into  which  the  retaining  wire  accurately 
fits,  and  are  designed  to  be  soft  soldered  to  the  bands. 
"  LL "  are  lengths  of  piano  wire  of  varying  sizes,  giving 
different  degrees  of  power. 

Other  devices  belonging  to  the  system  are  the  Plain 
Adjustable  Bands,  to  which  any  desired  attachments  can  be 
made.  Being  secured  to  the  anchor  teeth  by  means  of  the 
screw  and  nut  they  are  designed  for  use  where  a  cemented 
band  is  not  called  for. 

The  Anchor  Bands  have  tubes  soldered  to  them  through 
which  the  ends  of  the  Expansion  Arches  pass. 

The  Expansion  Arches  are  of  two  kinds. 

The  plain  arch  is  made  of  round  German  silver  wire, 
hard  drawn,  with  the  extremities  threaded  and  fitted  with 
shouldered  nuts. 


108  ORTHODONTIA. 

The  ribbed  arch  is  of  the  same  form  but  re-enforced  by  a 
finer  wire  soldered  to  its  outer  surface,  which  when  notched 
at  desired  points  prevents  the  wire  ligatures  from  slipping 
when  the  nuts  are  turned  to  force  the  arch  forward. 

The  Angle  Retraction  Arch,  Traction  Bar  and  other 
devices  will  be  found  illustrated  and  described  in  Part  III. 
Aside  from  the  advantages  of  simplicity,  efficiency  and 
cleanliness,  which  are  insured  by  these  appliances,  a  still 
greater  desideratum  is  gained  by  means  of  the  mechanical 
principles  observed  in  their  construction.  Stationary 
anchorage  and  non-relinquishment  of  pressure  are  promi- 
nent features  of  this  method,  and  are  certainly  secured 
almost  to  perfection. 

In  1899  Dr.  M.  A.  Knapp  brought  forward  his  set  of  regu- 
lating appliances,  which  included  many  features  not  pos- 
sessed by  those  previously  introduced. 

While  other  sets  or  systems  reduced  the  labor  of  construc- 
tion on  the  part  of  the  practitioner  to  a  minimum  by  fur- 
nishing many  parts  ready  made,  Dr.  Knapp's  idea  was  to 
eliminate  entirely  the  factor  of  individual  construction 
even  to  avoiding  the  necessity  for  taking  impressions  and 
making  models. 

To  do  away  with  soldering  in  the  construction  of  ordi- 
nary metal  bands,  his  bands 
are  made  of  straight  strips  of 
metal,  and  to  the  two  free  ends 
of  each,  stud  projections  or 
buttons  are  attached.  Ligature 
wire  draws  these  ends  as  closely 
together  as  possible  while  on 
the  tooth  and  is  then  woven 
about  the  studs  and  secured. 
After  the  band  is  thus  fitted 
it  is  removed  and  replaced 

with  cement.     The  method    of  fitting  the  band  is  shown 
in  Fig.  48. 


APPLIANCES    AND    METHODS. 


109 


FIG.  49 


FIG.  50. 


Besides  being  of  varying  lengths  to  properly  encircle  the 
different  teeth  each  band  has  attached  to  it  a  screw  stud 
or  a  tube  for  the  accommodation  of  other  accessories  in 
the  assembling  of  the  complete  device, 
as  illustrated  in  Fig.  49. 

The  peculiarity  of  the  Knapp  tube 
is  that  in  all  cases  it  is  a  tube  with  a 
slot  or  opening  along  its  entire  length, 
and  each  end  of  the  tube  (or  in  certain 
cases  only  one  end)  is  recessed  to 
receive  the  cylindrical  end  or  projec- 
tion of  the  nut  as  shown  in  Fig.  50. 

The  slot  in  the  tube  is  just  large 
enough  to  allow  the  threaded  end  of 
an  arch  wire,  or  other  wire  of  similar 
size,  to  pass  through  it  laterally,  after 
which  it  is  held  in  position  by  the 
nut  or  nuts  being  run  up  into  position 
within  and  against  the  ends  of  the  tube. 

The  object  of  this  slotted  tube  is  to  facilitate  the  placing 
of  the  wire  in  position  after  the  band  has  been  cemented  in 
place,  and  also  to  permit  of  its  easy  removal  without  dis- 
turbing the  band. 

No  other  system  uses  the  open  tube,  which  seems  to  be 
a  great  improvement  over  the  closed  tube  so  generally 
employed. 

Still  another  novel  feature  of  this  system  is  the  ball  and 
socket  joint  on  the  end  of  a  jack-screw  which  permits  the 
changing  of  the  direction  of  the  force  at  will. 

Many  other  ingenious  devices  are  included  in  the 
Knapp  system  which  cannot  here  be  dwelt  upon,  but  some 
of  them  will  be  illustrated  in  the  description  of  practical 
cases.* 


*  For  the  information  concerning  these  appliances  and  the  accompanying  illustra- 
tions the  author  is  indebted  to  Dr.  Knapp's  recently  published  work  entitled 
"  Orthodontia  Practically  Treated." 


110 


ORTHODONTIA. 


Fig.  51  represents  a  set  of  appliances  devised  and  manu- 
factured by  Mr.  J.  E.  Canning,  of  Denver.  The  special  fea- 
tures of  the  set 
which  distinguish 
it  from  others  of 
somewhat  similar 
character  are  the 
notched  arch  wire 
"A"  to  retain  liga- 
ture wires  securely 
and  compel  them 
to  travel  with  the 
moving  wire;  the 
indented  bands 
and  band  material 
designed  to  form  a 
better  surface  for 
the  adhesion  of 
cement ;  the  coiled 
wire  spring  on  the  jack  and  traction  screws  to  promote 
even  and  constant  pressure  and  the  friction  split-nut  which 
retains  a  firmer  grasp  on  the  threaded  wire  upon  which 
it  operates. 


SPECIAL   METHODS. 
COFFIN'S  METHOD. 

This  method  was  devised  by  Mr.  Lemuel  Coffin,  of  Lon- 
don, and  published  in  1881.  It  was  termed  the  "  Expan- 
sion Method,"  because  in  nearly  all  cases  a  certain  amount 
of  expansion  had  been  found  necessary  in  connection  with 
other  desired  movements. 

The  construction  of  the  appliance  and  the  principle  upon 
which  it  acts  are  exceedingly  simple.  The  power  is  derived 
from  the  elasticity  of  piano  wire,  attached  in  various  ways 
to  a  vulcanite  plate  which  covers  the  arch  (in  an  upper 


APPLIANCES    AND    METHODS.  Ill 

case)  and  envelops  the  posterior  teeth  on  each  side  to  give 
it  firmness  and  fixedness  in  position.  When  it  is  desired  to 
expand  the  upper  arch,  the  wire  is  bent  into  the  form  of  a 
double  U,  lying  on  top  of  the  plate  with  the  ends  embedded 
in  it. 

To  produce  lateral  expansion  in  the  lower  jaw,  the  form 
of  the  appliance  is  necessarily  different.  A  simple  vulcanite 
plate  is  made  in  horse-shoe  form,  fitting  the  gum  and  lingual 
surfaces  of  the  teeth,  and  capping  the  molars  and  bicus- 
pids. On  the  lingual  surface  of  this  plate,  lie  two  pieces  of 
piano  wire  suitably  curved,  with  their  ends  embedded  in 
the  rubber. 

Each  of  these  plates,  when  completed,  is  sawn  in  two 
along  the  median  line,  thus  allowing  the  tension  of  the  wire 
to  be  increased  from  time  to  time  by  spreading  apart  the 
sections  of  the  plate. 

The  piano  wire  used  may  be  obtained  from  piano  fac- 
tories or  from  dealers  in  dental  supplies.  For  ordinary 
cases  the  diameter  of  the  wire  should  be  between  three  and 
four  one-hundredths  of  an  inch,  a  lighter  or  heavier  num- 
ber yielding  respectively  less  or  greater  pressure. 

It  should  not  be  annealed,  though  it  may  be  tinned  after 
being  bent  to  shape,  to  prevent  oxidation  in  the  mouth,  but 
this  does  not  appear  to  be  necessary. 

A  wire  suitably  bent  to  produce  expansion  of  the  upper 
arch  is  represented  by  Fig.  52. 

The  details  of  the  construction  of  an  expansion  plate  for 

the  upper  jaw  are  as  follows  :  From 

,   ,,       .  FIG.  52 

an  accurate  impression  ot  the  jaw 

and    teeth,   taken  with    plaster    or 
modeling  compound,  a  plaster  model 
is  obtained.     This  model  should  be 
very  accurate  and  the  posterior  plas- 
ter teeth  to    which  the  plate  is  to  coffin  spring, 
cling   for  anchorage  should  be   slightly   scraped    at  their 
necks,  both  on  the  lingual   and   buccal  surfaces,  so  that 


112  ORTHODONTIA. 

the  finished  plate  will  have  to  be  sprung  into  place. 
Upon  this  a  wax  base-plate  is  fashioned,  to  cover  all  parts 
intended  to  be  covered  by  the  completed  plate.  The  suit- 
ably bent  wire  is  now  further  shaped  so  that  it  will  lie  upon 
the  exposed  surface  of  the  base-plate  and  conform  to  it 
as  closely  as  possible  in  outline.  After  the  ends  of  the  wire 
are  attached  to  the  base-plate  by  means  of  additional  wax, 
a  piece  of  tin-foil  (No.  60)  is  slipped  between  the  wire  and 
the  plate  and  its  corners  bent,  so  that  the  plaster  when 
poured  into  the  flask  will  grasp  and  remove  it  with  the 
wire.  The  foil  is  placed  there  so  that  the  plate  will  have  a 
polished  surface  under  the  wire  after  vulcanization.  The 
wax  base-plate  should  now  be  smoothed  with  a  spatula  and 
flasked  in  the  usual  manner.  In  separating  the  flask,  the 
wire  and  tin-foil  will  come  away  with  the  upper  half,  while 
the  model  will  remain  in  the  lower.  After  removing  the 
wax  and  packing  the  rubber,  the  case  is  vulcanized,  after 
which  it  is  polished.  The  completed  piece  should  now  be 
properly  fitted  to  the  patient's  mouth,  and  the  rubber  cover- 
ing the  masticating  surfaces  of  the  posterior  teeth  so  filed 
and  dressed  that  the  cusps  of  the  occluding  teeth  will  all 
strike  the  rubber  at  the  same  time. 

However  many  or  few  of  the  natural  teeth  be  covered  the 
last  ones  in  the  arch  must  always  be  included,  as  otherwise 
they  will  elongate  through  non-occlusion  and  thus  seri- 
ously impair  the  usefulness  of  the  masticatory  apparatus. 
After  the  plate  has  been  fitted  it  should  be  sawn  in  two  with 
a  jeweler's  fine  saw,  the  edges  made  smooth  and  slightly 
rounded,  and  the  case  introduced  into  the  mouth. 

It  is  desirable  to  have  the  patient  wear  the  plate  for  a 
day  without  enlargement,  after  which,  at  intervals  of  a  day 
or  two,  the  tension  of  the  wires  should  be  increased  by 
pulling  the  halves  of  the  plate  apart  sufficiently  to  slightly 
increase  the  space  between  them.  When  the  wire  is  heavy, 
as  is  necessary  where  great  force  is  to  be  exerted,  it  can  be 
best  formed  into  shape  and  afterwards  altered  as  required 


APPLIANCES    AND    METHODS. 


113 


FIG.  53. 


by  means  of  the  ordinary  clasp-bending  pliers.  The  con- 
struction of  the  lower  plate  is  substantially  the  same,  but 
the  wires  lie  against  the  plate  in  a  continuous  smooth  curve, 
instead  of  being  corrugated. 

Figs.  53  and  54  represent  an  upper  and  lower  expansion 
plate  as  described.  For  cases  where  expansion  is  not 
needed,  but  simply  the  moving  of  one  or  more  teeth,  Mr. 
Coffin  uses  a  solid  vulcanite  plate  with  wires  so  placed  as  to 
produce  the  de- 
sired movements. 
The  construction 
of  this  form  of  plate 
is  the  same  as  those 
just  described, 
with  the  exception 
of  the  shape  and 
arrangement  o  f 
the  wires  and  the 
non-separation  of 
the  plate. 

A  single  long 
piece  of  wire,  bent 
at  right  angles 
near  one  end  and 
flattened  at  the 
other,  is  embedded 
at  its  flattened  end 
into  the  plate, 
while  the  other 
end  and  a  long  portion  besides  is  free  and  lies  in  close 
contact  with  the  plate.  Before  the  wire  is  attached  to  the 
wax  base-plate,  the  plaster  tooth  representing  the  one  to  be 
moved  should  be  cut  away  close  to  its  neck  and  the  bent 
end  of  the  wire  laid  upon  the  stub  so  as  to  cover  the  entire 
diameter  of  the  stub  tooth.  In  this  position  it  is  vulcanized 
to  the  plate. 


Coffin's  Expansion  Plates. 


114 


ORTHODONTIA. 


When  the  plate  is  introduced  into  the  mouth  the  wire 
will  have  to  be  drawn  back  with  ^an  instrument  or  string 
before  the  plate  will  go  into  position.  Once  in  place  and 
the  wire  released  continuous  pressure  will  be  exerted  on  the 
malposed  tooth.  After  the  tension  of  the  wire  has  been  les- 
sened by  the  moving  of  the  tooth,  it  may  be  increased  either 
by  bending  the  wire  where  it  enters  the  plate  or  by  cutting 
it  out  and  re-setting  in  a  different  position. 

Another  and  very  convenient  way  of  lengthening  the 
wires  to  follow  the  moving  tooth,  is  to  slip  a  section  of 
German  silver  tubing  over  the  end  of  the  wire  and  soft- 
solder  it  in  position. 

Where  a  tooth  is  to  be  pressed  outward  the  wire  is 
anchored  in  the  palatal  portion  of  the  plate,  but  where  a 
tooth  is  to  be  moved  from  without  inward,  the  wire  should 
be  attached  to  that  portion  of  the  plate  covering  the  buccal 
surfaces  of  the  molars. 

Rotation  is  accomplished  by  combining  the  two  move- 
ments; that  is,  by  having  one  wire  on  the  lingual  surface 
to  press  against  one  angle  of  the  tooth,  and  another  on  the 
buccal  surface  to  press  against  the  opposite  angle. 

Two  wires  can  be  inserted  to  operate  on  two  teeth  at  the 

same  time,  either  in  sim- 
ilar or  opposite  directions. 
Fig.  55  represents  a  plate 
made  to  press  outward  two 
lateral  incisors. 

Many  modifications  of 
the  Coffin  plate  have  been 
devised  by  different  prac- 
•  itioners. 

The  originator  claims 
for  his  method  and  appli- 
ance, simplicity,  ease  of  construction  and  inexpensiveness, 
almost  universal  range  of  application,  perfect  control  of 
force  applied  and  direct  action,  comparative  painlessness 


FIG.  55. 


Coffin  Solid  Plate. 


APPLIANCES    AND    METHODS. 


115 


from  non-irritation  of  the  soft  tissues,  perfect  fixedness  and 
least  unsightliness,  ease  of  removal  for  cleansing,  and  little 
interference  with  speech  and  mastication. 

JACKSON'S  METHOD. 

Appreciating  the  value  of  spring-wire  as  a  power-yielding 
material,  as  shown  in  the  Coffin  method,  and  realizing  the 
advantage  in  most  cases  of  dispensing  with  the  use  of  a 
plate,  Dr.  V.  H.  Jackson  was  led  to  devise  a  method  of  con- 
structing regulating  appliances  in  which  piano-wire  was 
principally  employed. 

Later  experience  has  led  to  his  abandoning  the  use  of 
piano-wire  in  favor  of  hard  drawn  German  silver. 

By  suitably  bending  a  length  of  this  wire,  of  medium 
thickness,  in  such  a  way  as  to  pass  around  the  buccal  and 
lingual  surfaces  of  all  the  teeth  in  one  of  the  arches  and 
joining  these  portions  at  convenient  distances  by  short  con- 
necting wires,  a  "  crib"  or  skeleton-wire  fixture  was  formed 
that  hugged  the  teeth  and  held  itself  firmly  in  place. 

To  this,  as  a  foundation,  additional  wires  were  attached  of 
such  length  and  shape  as  to  bear  and  produce  pressure  upon 
any  teeth  in  the  same 
arch  which  it  was 
desired  to  bring  into 
proper  position. 

Fig.  56  shows  the 
general  appearance  of 
the"crib"in  its  simplest 
form. 

In  constructing  the 
appliance,  the  plaster 
teeth  of  the  model  are 
first  scraped  near  their 
necks  on  both  the  buc- 
cal and  lingual  surfaces  so  that  the  crib,  when  formed, 
will  have  to  be  sprung  into  place.  The  wire  is  now  bent 


FIG.  56. 


Crib     (Jackson). 


116  ORTHODONTIA. 

by  means  of  flat-  and  round-nosed  pliers  so  as  to  conform 
to  the  outline  of  the  teeth  and  touch  all  of  the  included 
ones  at  their  necks. 

To  keep  the  crib  from  impinging  upon  and  irritating  the 
gum,  short  wires  (as  before  stated)  are  formed  to  lie  in  the 
depressions  between  the  occlusal  surfaces  of  certain  teeth 
and  are  attached  to  the  main  wire  upon  both  the  buccal  and 
lingual  sides.  These  connecting  wires  are  joined  to  the  base 
wire  by  having  their  ends  bent  so  as  to  grasp  them,  after 
which  the  joints  are  secured  by  means  of  soft-solder  fused 
with  the  soldering  iron  while  the  parts  are  in  position  on 
the  model.  Before  soldering,  the  joints  will  have  to  be 
touched  with  dilute  muriate  of  zinc,  commonly  known  as 
soldering  fluid. 

The  crib  once  properly  formed,  additional  wires  for  pro- 
ducing pressure  at  any  point  and  in  any  desired  direction 
are  added  to  it  in  the  same  manner. 

Fig.  57  shows  a  crib  formed  for  and  attached  to  but  one 
F      57  side  of  the  arch  for  the  purpose  of 

moving  a  cuspid  labially  and  a  lat- 
eral lingually  into  line  at  the  same 
time. 

In  some  cases  the  end  of  the  wire 
producing  pressure  is  best  secured 
in  position  by  being  soldered  to  a 
band  to  be  cemented  to  the  tooth  to 
be  moved,  as  shown  in  Fig.  58. 

While    the   appliance    thus    con- 
structed is  firmly  held  in  place  by 
side  crib  (Jackson).       hugging  the  teeth  above  their  most 
prominent  portions  it  is  at  the  same  time  readily  removed 
for  the  purpose  of  bending  the  wire  springs  or  for  alter- 
ations or  new  attachments. 

In  constructing  these  anchorage  appliances,  we  first  cut 
from  pure  gold  plate,  gauge  35,  a  piece  large  enough  to  cover 
the  lingual  portion  of  the  anchor  tooth  and  contour  it  with 


APPLIANCES    AND    METHODS. 


117 


FIG.  58. 


FIG.  59. 


the  contouring  pliers  used  in  crown-  and  bridge-work.     A 

wire  crib  for  the  same  tooth  is  then  made  from  a  piece  of 

No.  21    German   silver 

wire  by  "  first  bending 

it  at  right  angles  (Fig. 

60),  leaving  the  width 

between     the     parallel 

sides  equal  to  the  antero- 

posterior     diameter    of 

the  tooth  to  be  clasped. 

The  part  that  is  to 
clasp  the  neck  of  the 
tooth  is  so  bent  with 
clasp-benders  that  it  Crib  and  Ban(L  (J<">kson) 

will  be  perfectly  adapted  to  the  curve  of  the  labial  side  of 
the  tooth.  (Fig.  61).  Both  arms  of  the  wire  are  next  bent  at 
nearly  a  right  angle 
at  a  proper  distance 
to  cause  them  to  pass 
over  the  occlusal  sur- 
face of  the  tooth,  and 
again  bent  in  the 
same  manner  to  ex- 
tend toward  the  neck 
of  the  tooth  on  the 
lingual  side.  (Fig.  62). 

"  The  ends  are  then 
bent     toward     each 

Other    near    the    gum  Anchorage.    (Jackson) 

line  over  the  piece  of  metal  previously  described,  as  seen  at 
A  in  Fig.  59,  and  tacked  with  soft  solder." 
If  the  wire  spring  is  to  be  attached  to 
the  teeth  on  the  opposite  side  of  the  arch 
a  similarly  constructed  crib  must  be  made 
for  that  side.  With  these  two  cribs  in 
place  on  the  plaster  model  the  connecting  wire,  after  being 
suitably  shaped,  is  laid  in  position  and  firmly  held  while 


FIG.  60. 


118 


ORTHODONTIA. 


FlO.  61. 


FIG.  62 


FIG.  63. 


all  are  joined  together  with  solder.  The  soldering  is  most 
conveniently  accomplished  by  moistening  the  parts  with 
dilute  muriate  of  zinc,  laying  upon  each 
joint  a  piece  of  soft  solder  of  suitable  size 
and  fusing  with  a  soldering  iron.  After  this 
any  wire  springs  that  may  be  needed  are 
attached  in  the  same  manner. 
The  entire  appliance  being  thus  formed  of 
separate  parts  and  joined  together  while  in 
position  on  the  model  assures  accuracy  of  fit 
that  could  not  well  be  obtained  in  any  other 
manner. 

Where  lateral  expansion  of  the  arch  is  desired  a  heavy 
wire  (No.  14)  is  bent  to  follow  the  line  of  the  roof  of  the 
mouth  from  molar  to  molar  and  then  extend  along  the 
crib  on  the  anchor  teeth  on  each  side,  to  which  it  is  attached. 

Fig.  63  shows  this 
form  completed  on 
one  side  only. 

Some  of  the  nu- 
merous ways  in 
which  these  combi- 
nation appliances 
may  be  adapted  to 
the  correction  of 
many  forms  of 
irregularity  are 
shown  in  connec- 
tion with  the  prac- 
tical treatment  of 
cases  in  Part  III. 
Dr.  Jackson  claims  for  his  method  the  following  advan- 
tages : 

1.  "  The  materials  are  inexpensive  and  within  the  reach 
of  all." 

2.  "The   crib   and   spring   construction   is   simple   and 
quickly  done." 


Jackson  Crib-(  partly  constructed.) 


APPLIANCES    AND    METHODS.  119 

3.  "  The  clinging  grip  of  the  crib  on  its  anchorage  is  suffi- 
cient to  hold  the  fixture  firmly,  yet  it  is  easily  sprung  off 
for  cleansing  or  change." 

4.  "  Changes  or  additions  are  easily  and  quickly  made." 

5.  "  The  structure  is  light,  cleanly  and  occupies  the  least 
possible  space  in  the  mouth." 

6.  "  Its  action  is  controllable  and  free  from  risk  of  over- 
action." 

7.  "  It  forms  a  perfect  retainer." 

The  system  certainly  possesses  great  merit,  as  shown  by 
the  commendations  of  those  who  have  adopted  and  used  it. 
Many  who  do  not  use  the  system  as  a  whole  use  the  crib  in 
its  various  forms  as  a  retainer.  For  such  purpose  it  is  most 
admirable  on  account  of  its  simplicity  and  inconspicuous- 
ness. 

AINSWORTH'S   METHOD. 

Following  in  the  line  of  producing  desired  movements  of 
teeth  through  the  agency  of  spring  wire,  Dr.  George  C. 
Ainsworth,  in  March,  1904,  gave  to  the  profession  his 
method  of  constructing  appliances  operating  upon  this 
principle.* 

Designed  for  the  purpose  of  expanding  the  arch  as  pre- 
liminary to  bringing  into  alignment  crowded  teeth,  either 
in  the  anterior  or  buccal  region,  Dr.  Ainsworth  has  desig- 
nated it  the  "  self-acting  spreading  appliance."  Of  it  he 
says  :  "  It  may  have  a  double  action — i.  e.,  it  can  be  so  ad- 
justed as  to  spread  the  arch  and,  when  desirable,  retract  the 
incisors  at  the  same  time;  or,  by  the  addition  of  ligatures, 
the  front  teeth  may  be  moved  forward  or  elongated.  In 
accomplishing  the  first  two,  it  is  entirely  self-acting  and 
requires  very  little  attention,  often  allowing  the  absence  of 
the  patient  for  weeks  at  a  time." 

Its  construction  is  described  as  follows : 

"This  appliance,  in   its  simplest  form,    is  composed  of 

*  International  Dental  Journal,  July,  1904. 


120 


ORTHODONTIA. 


three  members  (Fig.  64  A) — two  anchors  and  a  wire  spring, 
while  the  compound  form  has  two  springs.  Each  anchor 
is  made  up  of  three  pieces — a  piece  of  seamless  tubing,  with 


FIG.  64. 


Ainsworth's  Expansion  Devices. 

30-gauge  walls,  of  suitable  size  and  length  to  be  fitted  to  the 
tooth  chosen  for  anchorage,  after  the  manner  of  forming  a 
band  for  a  gold  crown.  To  this  is  soldered,  on  the  lingual 


APPLIANCES    AND    METHODS. 


121 


side,  horizontally,  a  piece  of  16-gauge  wire  running  along 
the  border  of  the  arch,  with  a  bearing  on  and  of  sufficient 
length  to  engage  all  of  the  teeth  to  be  moved  on  that  side  ; 
while  on  the  buccal  side  of  the  anchor  band  is  soldered  a 
short  piece  of  16-gauge  seamless  tubing,  placed  vertically, 
to  receive  the  end  of  the  spring  wire,  the  active  principle  of 
the  appliance.  These  anchors,  when  completed,  are  adjusted 
to  the  teeth  selected,  and  cemented  firmly  into  place 
(B) — one  on  each  side  of  the  arch,  after  which  the  two 
ends  of  the  spring  wire,  bent  at  right  angles  to  itself,  are 
sprung  into  the  tubes  provided  for  them  (C).  The  inside 
bar  is  designed  to  move  the  bicuspids  and  molars  as  a  unit 
without  the  aid  of  ligatures. 

In  this  case  the  sides  of  the  arch  are  to  be  equally 
expanded  and  the  incisors  moved  in  (D).  The  teeth  to 
be  moved  out  include  the  cuspids,  the  bicuspids  and  the 
first  molars.  The  FIG.  65. 

spring,  being  ad- 
justed to  bear 
firmly  onthe  labial 
surface  of  the  inci- 
sors, presses  those 
teeth  in  as  the  side 
teeth  move  out. 
The  teeth  chosen 
for  attaching  the 
anchor  bands 
should  be  midway 
between  the  two 
points  of  resist- 
ance, and  this,  Re-enforced  Anchorage  (Ainsworth). 

perhaps,  more  often  than  otherwise,  falls  on  the  first  bicuspid, 
though  sometimes  it  may  be  the  second  bicuspid,  or  even 
the  first  molar." 

Fig.  65  represents  a  completed  case  in  which  five  teeth  on 
the  left  side  were  used  as  anchorage  in  moving  buccally 


122  ORTHODONTIA. 

the  second  bicuspid  on  the  right  side,  which  had  been  in 

lingual  malposition. 

In  eight  weeks  the  tooth  had  moved  into  position  with 

practically  no  alteration  or  change  and  without  any  pain 

or  inconvenience  whatever. 

Fig.  66  illustrates  a  case  in  which  the  age  of  the  patient 

(forty-five  to  fifty  years)  required  the  employment  of  greater 
FIG.  66.  force    to    bring 

about  the  widen- 
ing of  the  arch, 
both  in  the  cuspid 
and  molar  regions. 
In  this  case  two 
spring  wires  were 
used,  one  acting  on 
the  cuspids,  being 
in  the  lower  and 
usual  position, 
while  the  longer 
one,  acting  on  the 
molars,  was  adjus- 
ted high  up  under 
the  lip  so  as  to  be 

Widening  o.  the  Arch  (Ainsworth).  invisible. 

It  will  be  observed  that  the  tubes  on  the  molar  bands  run 
high  up  opposite  the  ends  of  the  roots.  Tins  was  for  the 
purpose  of  applying  the  expanding  pressure  in  such  a  way 
as  to  move  the  roots  and  process  at  that  point,  the  long  ends 
of  the  spring  wire  being  bent  out  at  such  an  angle  as  to 
exert  force  there  when  inserted  in  the  tubes. 

After  lateral  expansion  had  been  accomplished  the 
anterior  teeth  were  brought  into  alignment. 

In  Fig.  67  A  shows  the  appliance  when  placed  in  position 
and  B  the  case  completed. 


APPLIANCES    AND    METHODS. 


CONSTRUCTION. 


123 


In  making  these  appliances  ordinary  German  silver  is 
used  for  all  except  the  spring  wire,  which  is  eighteen  per 
cent,  nickel  especially  drawn  for  the  purpose,  with  the 
maximum  amount  of  spring  obtainable  consistent  with 
toughness.  If  too  hard  it  is  apt  to  break  and  cause  annoy  - 


FIG.  67. 


Arch  Expansion  Completed  (Ainsworth). 

ance.  I  have  obtained  it  of  the  Holmes,  Booth  &  Hay- 
dens  Company,  of  Waterbury,  Conn.  The  tubing,  of  vari- 
ous sizes,  is  seamless  drawn,  and  especially  made  for  me 
by  J.  Briggs  &  Sons'  Company,  65  Clifford  Street,  Provi- 
dence, R.  I." 

"  Ordinary  plate,  of  German  silver  or  gold,  may  be  used, 
with  platinous  gold  wire  for  the  spring,  if  one  prefers,  but  I 


124  ORTHODONTIA. 

have  found  the  German  silver  to  answer  every  purpose,  and 
in  some  respects  it  is  superior.  Seamless  drawn  tubing  for 
the  anchor  bands  possesses  a  marked  advantage,  particu- 
larly when  soldering  the  small  tubes  to  them.  The  appli- 
ance when  completed  is  gold-plated. 

"  In  making  the  appliance  the  method  of  procedure  is  as 
follows :  After  cutting  off  a  piece  of  seamless  tubing  of  the 
proper  size,  anneal  it,  and  with  a  pair  of  contouring  pliers 
form  it  into  a  sort  of  barrel-shaped  cylinder;  next,  with  a 
small  pair  of  scissors  cut  away  a  part  of  one  end  to  approxi- 
mately correspond  to  the  gum  line  around  the  tooth ;  then 
gradually  work  it  up  into  position,  perhaps  a  little  under 
the  gum,  take  an  instrument  and  mark  around  at  the  gum 
line ;  also  at  the  top,  so  that  there  shall  be  a  small  projection 
left  after  trimming  to  turn  over  the  edge  of  the  tooth  into 
the  sulci,  giving  the  band  a  firm  seat  when  finally  cemented 
to  place.  After  trimming,  the  two  bands  are  placed  in  posi- 
tion and  a  plaster  impression  taken ;  this,  in  my  judgment, 
is  important,  as  accuracy  counts  for  much  when  one  comes 
to  set  the  appliance. 

"  As  a  rule,  it  is  reasonably  possible  to  force  a  band  of  30- 
gauge  walls  between  the  teeth,  but  sometimes,  as  an  aid,  I 
draw  in  some  sort  of  a  wedge  for  fifteen  minutes  or  an  hour, 
as  the  case  may  be.  A  rubber  wedge  works  well  for  that 
length  of  time.  Then,  again,  the  edges  of  the  band  may  be 
thinned  a  little  and  smeared  with  vaseline ;  one  band  may 
be  crowded  in  a  trifle  and  left  while  proceeding  with  the 
other.  In  short,  a  variety  of  expedients  may  be  resorted  to, 
that  will  be  suggested  to  the  mind  of  the  resourceful  man." 

"After  the  impression  has  been  removed  from  the  mouth 
the  bands  are  carefully  taken  off  and  replaced  in  the 
impression,  and  the  usual  detail  of  making  the  model  gone 
through  with,  the  bands  appearing  on  it  exactly  as  they 
will  stand  in  the  mouth.  Proceed  then  to  adjust  the 
lingual  wires  to  fit  the  model  as  desired,  being  particularly 
careful,  if  intending  to  move  the  cuspids  out,  to  turn  that 


APPLIANCES    AND    METHODS.  125 

end  of  the  wire  well  up  under  the  gum  in  such  a  way  as  to 
engage  that  tooth  above  the  bulge  of  enamel ;  otherwise, 
when  the  spring  pressure  is  applied  that  end  of  the  wire 
will  slide  down  the  inclined  plane  surface  of  the  cuspid 
instead  of  moving  the  tooth,  resulting  in  a  troublesome 
elongation  of  the  tooth  banded. 

"  When  these  wires  have  been  properly  fitted,  hold  them  in 
position  by  pieces  of  binding  wire  passed  around  them  and 
through  the  model,  twisting  the  ends  till  taut. 

"  Next,  to  adjust  the  small  tubes  for  receiving  the  ends  of 
the  spring-wire,  pass  an  ordinary  pin  through  them  into  the 
model  in  such  a  way  as  to  hold  them  in  position  while 
being  soldered 

"  Next,  bur  out  a  little  of  the  plaster,  from  within  the 
anchor  band  opposite  the  points  where  the  solder  is  to  flow, 
and  proceed  to  the  soldering,  which  is  done  on  the  model. 

"  The  next  step  is  to  remove,  finish,  polish,  and  gold  plate. 
'  "  The  labial  spring-wire  is  usually  fitted  into  position  after 
the  anchors  are  placed  in  the  mouth,  sometimes  before 
cementing,  sometimes  after.  If  the  front  teeth  are  to  be 
moved  in  and  spaces  closed  up,  the  wire  is  adjusted  to  bear 
as  firmly  as  possible  on  those  teeth ;  if  the  front  teeth  are  to 
be  moved  out,  the  wire  is  adjusted  to  stand  out  a  bit  to 
admit  of  the  ligatures  doing  their  work.  Under  favorable 
conditions,  the  fitting  of  the  anchor  bands  and  taking  the 
impression  can  be  accomplished  in  an  hour. 

"  In  summing  up  the  advantages  of  this  appliance  we  may 
mention  its  simplicity,  its  cleanliness  and  its  effectiveness. 

"  It  is  worn  twenty -four  hours  every  day,  and  interferes  as 
little  as  possible  with  the  ordinary  functions  of  the  teeth 
and  mouth. 

"  It  is- automatic  in  its  action,  and  may  be  adjusted  so  as  to 
have  a  double  or,  by  the  addition  of  ligatures,  a  triple  action, 
— i.e.,  it  will  spread  the  arch,  move  the  front  teeth  in,  and 
elongate  at  the  same  time. 

"  It  is  equally  applicable  to  the  upper  or  lower  teeth  and 
may  be  used  on  both  simultaneously. 


126  ORTHODONTIA. 

"  It  is  conveniently  adjusted  to  bring  pressure  to  bear  on 
the  roots  and  alveolus,  and  thus  has  a  tendency  to  overcome 
the  outward  tipping  of  the  anchor  teeth  sometimes  encoun- 
tered in  spreading  the  arch." 

Two  other  devices  of  Dr.  Ainsworth,  one,  "  an  inclined 
plane  to  assist  in  correcting  occlusion "  and  the  other  a 
"  regulating  device,"  are  shown  and  described  under  their 
respective  headings. 


CHAPTER  IV. 

RETAINING  APPLIANCES. 

In  order  to  retain  the  results  gained  in  regulating  it  is 
absolutely  necessary  that  the  teeth  be  firmly  held  in  their 
new  positions  until  all  tendency  to  move  back  toward  or  into 
their  old  positions  has  been  overcome.  This  is  quite  as 
important  as  their  regulation  and,  in  some  cases,  quite  as 
difficult. 

Teeth  become  firm  in  their  new  positions  by  virtue  of  a 
deposit  of  osseous  material  in  the  space  created  by  their 
movement.  The  formation  and  perfect  ossification  of  this 
new  material  is  only  completed  after  a  lapse  of  time  vary- 
ing with  the  age  of  the  patient  and  the  extent  to  which  the 
teeth  have  been  moved.  Experience  has  proven  that  a  less 
time  than  six  months  should  never  be  allowed  for  it,  while 
in  persons  of  mature  age  or  in  those  younger  where  many 
teeth  have  been  involved,  the  time  will  sometimes  have  to 
be  extended  to  a  year  and  in  complicated  or  extensive  cases 
even  to  two  years. 

The  natural  tendency  of  a  tooth  to  return  to  its  former 
position,  aided  by  the  tension  of  the  parts  that  have  resisted 
its  movement,  will  certainly  move  a  tooth  from  its  new 
position  unless  the  newly  formed  process  has  become  thor- 
oughly calcified,  and  is  thus  by  its  strength  and  density 
able  to  resist  the  opposing  forces.  Numberless  failures  to 
retain  the  good  results  of  regulation  are  attributable  to  this 
cause  alone. 

In  cases  where  an  upper  incisior  has  been  occluding  lin- 
gually  to  the  lower  ones  or  where  a  lower  one  has  been  occlu- 
ding labially  to  the  upper  ones,  no  retaining  appliance  will 
need  to  be  worn  because  the  restored  normal  occlusion  will 
prevent  the  tooth  from  returning  to  its  former  position. 

127 


128 


ORTHODONTIA. 


So,  with  the  bicuspids  and  molars;  when  malocclusion 
has  either  forced  or  kept  them  out  of  their  natural  positions, 
the  restoration  of  normal  occlusion  will  often  greatly  aid  in 
keeping  them  in  place. 

In  all  other  cases,  however,  mechanical  assistance  will  be 
necessary  until  the  teeth  have  become  firm.  Where  the 
arch  or  any  portion  of  it  has  been  enlarged,  or  where  a  num- 
ber of  teeth  have  been  moved  from  within  outward,  the 
simplest  and  probably  the  best  means  of  retaining  them  will 
be  the  wearing  of  a  thin  vulcanite  or  metal  plate  covering 
the  palatal  arch  and  nicely  fitting  each  tooth  at  its  neck.  It 
may  contain  a  vacuum-chamber  or  not,  as  preferred,  but  in 
many  cases  the  use  of  one  will  greatly  assist  in  keeping  the 
plate  in  place.  In  addition  to  its  use  in  preventing  teeth 
from  moving  inward,  the  plate  may  often  advantageously 
be  modified  by  the  addition  of  a  gold  hook  or  spur  to  keep 
rotated  teeth  in  position,  or  to  retain  individual  teeth  that 

have  been  moved  inward. 
Where  the  bicuspid  and 
molar  teeth  have  not  been 
disturbed  and  merely  a 
rearrangement  of  the 
anterior  ones  has  been 
effected  the  author  has 
found  great  satisfaction  in 
the  employment  of  a  small 
vulcanite  plate  with  gold 
wire  extension  as  shown 
in  Fig.  68.  The  plate  fits, 
each  tooth  in  the  arch  at 
its  neck,  while  the  fine 
platinous  gold  wire  passes  out  between  the  occlusal  spaces  * 
on  each  side  and  lies  along  the  labial  surfaces  of  the  inclu- 
ded teeth. 

While  vulcanite  plates  in  some  form,  either  by  them- 
selves or  in  combination  with  accessories,  are  frequently 


FIG.  68. 


Retainer. 


RETAINING    APPLIANCES. 


129 


FIG.  69. 


used  for  retaining  corrected  teeth,  their  use  is  open  to  cer- 
tain objections.  All  plates,  used  either  for  correction  or 
retention,  must  be  removed  at  frequent  intervals  for  cleans- 
ing. The  very  necessity  for  their  removal  affords  oppor- 
tunity for  the  patient  to  remove  them  at  other  times,  and 
possibly  forget  or  wilfully  neglect  to  reinsert  them  for  a 
longer  or  shorter  period,  thus  causing  delay  in  the  repara- 
tive  process. 

Besides  this,  also,  in  the  very  act  of  removal  and  insertion 
the  teeth  are  slightly  moved  in  their  sockets  and  this  will 
to  a  certain  degree  hinder  the  reformation  of  tissue. 

On  account  of  these  objectionable  features  the  author  has 
for  many  years  avoided  the  use  of  vulcanite  retaining  plates, 
wherever  he  could  do  without  them.  As  a  substitute  he 
was  led  to  devise  a 
number  of  little  ap- 
pliances of  gold  and 
platinum,  occupying 
the  least  possible 
space,  and  firmly 
attached  to  the  teeth 
for  the  required  time. 
Fig.  69  shows  one  of 
these  appliances  in 
its  simplest  form.  It 

Consists    of    a    platin-  'A'ue  Author's  Band  and  Bar  Retainer. 

um  (Magill)  band,  fitted  to  the  tooth,  and  having  a  gold 
bar  or  spur  soldered  to  it  to  press  or  bear  against  one  or 
more  of  the  adjoining  teeth.  When  properly  adjusted  it  is 
secured  to  the  corrected  tooth  by  means  of  zinc  phosphate. 

Its  advantages  consist  in  its  small  size,  its  slight  contact 
with  teeth  other  than  the  one  upon  which  it  is  placed,  its 
cleanliness,  its  fixedness  and  the  firmness  with  which  it 
holds  the  corrected  tooth  in  place. 

The  latter  is  its  most  important  feature,  for  it  is  a  well 
recognized  fact  in  surgical  practice  that  formation  of  bony 


130 


ORTHODONTIA. 


FIG.   70. 


Retainer. 


FIG.  71. 


Retainer. 


FIG.  72. 


tissue  will  progress  in  rapidity  proportionate  to  the  immo- 
bility of  the  parts. 

Fig.  70  shows  a  modification  where  two  teeth  are  thus  to 
be  retained  with  the  extension  bar  long 
enough  to  include  more  distant  teeth.  Fig. 
71  represents  metal  bands  joined  at  their 
points  of  contact,  for  the  retention  of  two 
teeth  that  have  been  rotated. 

Any  number  of  bands  may  thus  be  joined 
to  form  a  retainer  for  a  corresponding  num- 
ber of  teeth,  but  where  they  occupy  so  much 
interdental  space,  the  separations  between 
the  teeth  are  very  unsightly  after  the  retainer 
has  been  removed.  A  better  plan  is  to  employ  but  two  bands, 
if  possible,  and  allow  extensions  from  these  to  support  and 

steady  any  intervening 
ones.  An  illustration  of 
one  manner  of  doing  this 
is  shown  in  Fig.  72.  In 
this  case  the  two  bands  on 
the  cuspids  are  united  by 
a  thin  gold  or  platinum 
wire  passing  along  and 
conforming-  in  outline  to 
the  labial  surfaces  of  the 

Band  and  wire  Retainer.  intervening  teeth.     It  was 

used  to  retain  three  incisor 
teeth  which  had  been 
drawn  inward. 

Fig.  73  illustrates  a  re- 
tainer of  nearly  similar 
character  for  the  lower 
incisors.  In  this  case  a 
band  of  gold  takes  the 
place  of  the  wire  on  account  of  its  greater  stiffness. 

Retaining  appliances  of  this  character  cannot,  of  course, 


FIG    73. 


Retainer  for  Lower  Incisors. 


RETAINING    APPLIANCES. 


131 


be  used  to  advantage  in  all  cases,  but  where  they  can  they 
will  be  found  to  be  most  satisfactory. 

FIG.  74. 


Fig.  74  represents  a  variety  of  retainers  constructed  on 
the   band    and    bar    principle,   showing  FIG.  75. 

numerous  modifications. 

A  very  simple  appliance  for  holding 
teeth  which  have  been  drawn  toward  one 
another  is  shown  in  Fig.  75,  and  was  de- 
vised by  Prof.  C.  S.  Case.  It  consists  of 
a  silver  or  platinum  wire  passed  over  lugs 
or  pins  upon  bands  attached  to  the  teeth 
to  be  retained.  Floss  silk  or  China-grass 
line,  used  in  the  same  manner  would 
answer  instead  of  wire,  but  it  would  bejneither  as  strong  nor 
as  cleanly.  Prof.  Case  also  uses  the  wire  for  exerting  a 


Retainer  (Case). 


132 


ORTHODONTIA. 


FIG.  76. 


gentle  tractile  force  where  needed  by  soldering  a  piece  of 
square  metal  tubing  to  it  at  about  the -middle  of  its  length 
and  turning  this  with  a  suitable  instrument,  thus  twisting 
the  wires  and  drawing  the  teeth  together. 

Another  form  of  retainer  for  complicated  cases  is  shown 

in  Fig.  76.  It 
was  devised  by 
Dr.  Ainsworth, 
and  of  it  he  says: 
*"The  appliance 
is  composed  of 
bands  with 
small  tubes 
attached  verti- 
cally to  their 
buccal  sides  and 
cemented  to  the 
anchor  teeth. 
To  the  lingual 
surfaces  of  the 
bands  is  solder- 
ed a  wire  ex- 
tending around 
and  touching 
all  or  most  of 
the  teeth  on 
their  lingual 
aspect.  This  re- 
tains in  position 
all  of  the  teeth 

Ainsworth's  Retainer.  that    ha^e   been 

moved  outward. 

A  labial  wire,  suitably  curved  with  its  ends  bent  at  right 
angles  is  inserted  into  the  tubes  of  the  anchor  bands.  This 
retains  the  teeth  that  have  been  moved  lingually. 


*  International  Dental  Journal,  July,  1904. 


RETAINING    APPLIANCES.  133 

The  labial  wire  can  be  removed  and  replaced  when 
desired,  thus  enabling  it  to  be  dispensed  with  for  an  evening 
or  for  some  special  occasion." 

Other  modes  of  retention  will  often  suggest  themselves 
to  the  inventive  mind  of  the  orthodontist,  but  in  the  devis- 
ing of  any  appliance  for  this  purpose  the  essential  qualities 
of  simplicity,  fixedness,  inconspicuousness  and  harmless- 
ness  must  ever  be  kept  in  view. 


CHAPTER  V. 

OUTLINE  OF  COLLEGE  TECHNIC  COURSE. 

In  teaching  Orthodontia  Technics  the  proposed  course 
should  be  well  mapped  out  and  divided  into  as  many  parts 
as  may  seem  necessary.  The  class  (usually  the  Freshman), 
should  be  arranged  in  sections  of  eight  or  ten  each  so  that 
every  student  may  receive  as  much  individual  benefit  from 
each  demonstration  as  possible. 

The  demonstrator  or  instructor  should  be  provided  with 
a  small  class  room,  furnished  with  work  bench  or  table,  gas, 
water  and  all  necessary  tools  for  his  use. 

One  section  should  be  taken  into  the  room  at  a  time  and 
the  demonstrator  devote  an  hour  to  explaining  and  demon- 
strating the  first  part  of  the  work.  He  should  not  only  per- 
form the  work  but  explain  the  proper  method  of  doing  it. 
The  instruments  or  tools  of  each  member  of  the  section 
should  now  be  inspected  to  see  that  the  full  equipment  has 
been  provided,  and  the  section  be  given  one  or  two  half  days 
in  which  to  do  the  apportioned  work.  At  the  end  of  this 
time  the  work  should  be  submitted  for  inspection  and  if 
satisfactory,  credit  for  the  same  should  be  given  by  punch- 
ing the  student's  card. 

All  the  sections  in  turn  are  given  this  same  demonstration 
and  required  to  fulfill  the  same  requirements. 

The  second  part  is  then  taken  up  in  like  manner,  begin- 
ning with  the  first  section  and  proceeding  to  the  last,  and  so 
the  subsequent  parts  in  turn. 

In  this  wtiy  a  systematic  and  progressive  course  can  be 
carried  through,  occupying  on  the  student's  part  probably 
not  more  than  fifty  hours  during  the  term. 

The  demonstrator  should  be  skilful  with  his  hands,  under- 
stand his  subject  thoroughly,  be  able  to  impart  instruction, 
exercise  tact  and  authority  as  well  and  be  a  strict  disciplin- 
arian. 

134 


OUTLINE    OF    TECHNIC    COURSE.  135 

In  addition,  before  beginning  the  course,  he  should  con- 
struct samples  of  the  various  parts  or  pieces  to  be  made, 
arrange  them  in  sequence  upon  a  large  card  and  plainly 
label  them. 

This  card  should  be  framed  under  glass  and  fastened  to 
the  wall  of  the  laboratory  or  class  room  at  a  place  where  it 
will  be  convenient  for  the  students  to  examine  it. 

The  first  requirement  in  the  course  should  be  the  taking 
of  three  or  four  impressions  of  fellow  members'  mouths  with 
modeling  compound  and  the  making  of  upper  and  lower 
models  from  them. 

When  he  has  become  proficient  in  this  he  should  be 
taught  to  take  similar  impressions  with  plaster  and  again 
make  models  from  these.  As  good  models  are  the  basis  of 
good  work  in  Orthodontia  the  student  should  be  required  to  be 
proficient  in  the  making  of  them  before  proceeding  farther. 

The  base  of  the  models  should  be  parallel  with  the  occlu- 
sal  line  of  the  teeth,  at  least  one  inch  in  thickness  and  neatly 
trimmed.  If  any  bubbles  or  imperfections  appear  in  them 
they  can  be  remedied  with  thinly-mixed  plaster  applied 
with  a  delicate  camels-hair  brush. 

The  models,  completed  with  all  exactness,  are  preserved 
for  purposes  of  reference  and  comparison.  They  should 
never  be  varnished. 

Partial  impressions  of  different  sections  of  the  arch  should 
also  be  taken  and  the  models  made  from  these  used  as 
"  working  models  "  in  the  construction  of  bands  and  appli- 
ances. 

After  this  preparatory  work,  he  should  be  taught  the 
drawing  of  wire  and  tubing,  the  measurement  for  and  con- 
struction of  various  kinds  of  bands  and  attachment,  the 
joining  of  wire  and  tubing,  the  making  of  screws,  nuts,  jack 
and  drag-screws,  soldering  clips,  etc. 

Plate  A  is  presented  as  a  suggestive  outline  of  a  course  in 
the  shaping  of  raw  material  and  the  construction  of  repre- 
sentative parts  of  regulating  appliances.  It  is  a  reproduc- 
tion of  one  used  by  the  author  during  the  past  college  term. 


136 


ORTHODONTIA. 

PLATE  A. 


/. 
2. 


00* 


d  O 


/*-.     /J-.       /£ 


OUTLINE    OF    TECHNIC    COURSE.  137 

Its  explanation  is  as  follows : 

1.  G.  S.  wire,  No  12.     Anneal,  file  to  long  point  at  one 
end  and  draw  down  to  No.  17.     This  corresponds  to  hole 
No.  36  in  Joubert  draw  plate. 

2.  The  same  drawn  down. 

3.  Piece  of  G.  S.  plate,  No.  27,  half  inch  wide  and  six 
inches  long. 

4.  5.     Same  cut  lengthwise  into  two  strips  and  pointed 
at  end.     Anneal  and  draw  down  until  it  will  just  receive 
No.  17  wire. 

6.  Tubing  completed. 

7.  Piece  of  G.  S.  wire,  No.  9,  and  three  and  a  half  inches 
long  for  making  of  wrench. 

8.  End  forged  flat  and  bent  at  angle. 

9.  Same,  with  slot  filed  in  end  to  fit  nuts. 

10.  Bicuspid  band  with  lap-joint. 

11.  Molar  band  with  flush-joint. 

12.  Incisor  band  with  lap. 

13.  Incisor  band  with  hook  attachment. 

14.  Molar  band  with  headed  pin  attachment. 

15.  Band  with  vertical  tube. 

16.  Band  with  horizontal  tube. 

17.  Short  piece  of  No.  17  wire. 

18.  Retaining  tube,  open. 

19.  Rotating  tubing. 

20.  Tubing  with  soldered  joint. 

21.  Elliptical  tubing. 

22.  Nuts  drilled  and  tapped. 

23.  Threaded  wire  and  nut. 

24.  Same,  formed  into  drag-screw. 

25.  Jackscrew  and  sleeve. 

26.  Elliptical  tubing  drilled  for  point  of  jackscrew. 

27.  Elliptical  tubing  with  slots  to  receive  tail  of  jack- 
screw. 

28.  Two  pieces  of  wire  to  be  joined  by  soldering. 

29.  Same  joined. 


138  ORTHODONTIA. 

30.  Large  and  small  wire  joined. 

31.  Pieces  of  tubing  to  be  joined. 

32.  Same  united. 

33.  Tubing  joined  at  various  angles. 
34-38.     Piano-wire  soldering  clips. 

After  the  making  of  these  various  parts,  which  are 
intended  only  to  teach  the  proper  method  of  their  construc- 
tion, two  or  more  devices  of  popular  type  should  be  assigned 
to  each  student  for  construction.  For  this  purpose  a  suit- 
able model  must  be  provided. 

Teeth  made  of  white  vulcanite  or  celluloid,  copied  from 
natural  forms,  are  now  in  the  market  and  can  be  purchased 
from  the  dealers.  An  upper  set  of  these,  arranged  in  the 
normal  arch  line  in  a  plaster  model  will  answer  every 
purpose.  The  student  should  be  required  to  make  each 
band  to  accurately  fit  the  tooth  to  which  it  is  to  be  applied 
and  to  do  so  without  in  any  way  marring  or  changing  its 
form.  Every  other  part  of  the  proposed  appliance  should 
in  like  manner  be  made  and  accurately  adjusted  to  its 
proper  position  on  the  model. 

This  will  teach  exactness  in  construction  which  could  be 
attained  in  no  other  way  out  of  the  mouth.  Making  and 
fitting  appliances  to  plaster  teeth,  as  was  once  the  custom, 
is  worse  than  useless  for  it  is  productive  of  inaccuracy  and 
tempts  the  student  to  trim  the  tooth  to  fit  the  appliance. 
A  course  of  this  general  character  with  such  variations  as 
may  seem  best  to  the  instructor,  will  well  qualify  the  stu- 
dent to  undertake  the  construction  of  appliances  for  prac- 
tical cases  in  the  college  infirmary  during  his  succeeding 
year. 


PART  III. 

CLASSIFICATION  OF  IRREGULARITIES 
AND  PRACTICAL  TREATMENT. 

In  the  classification  of  irregularities  it  has  seemed  best 
not  to  base  the  varieties  upon  simple  occlusion  of  the  teeth 
but  to  arrange  them  into  groups  or  classes,  each  class 
having  certain  distinctive  characteristics.  In  this  way,  by 
noticing  the  characteristics  in  any  case  it  may  easily  be 
referred  to  its  proper  class,  where  all  matters  relating  to  its 
treatment  will  be  found. 

Occlusion  has  much  to  do  with  both  the  causes  for  and 
the  proper  treatment  of  irregularities,  but  to  base  a  system 
of  classification  entirely  upon  it  would  be  at  variance  with 
the  custom  prevailing  in  other  departments  of  natural 
science  where  marked  physical  characteristics,  their  corre- 
spondence or  their  variation  are  made  the  basis  for  arrange- 
ment into  separate  orders  or  classes. 

There  are  two  natural  general  divisions  which  include 
all  forms  of  irregularity  commonly  met  with. 

The  first  of  these  is  "  Simple  Irregularities,"  including  all 
those  lesser  malpositions  in  which  but  few  teeth  are  involved 
and  where  such  malposition  bears  no  important  relation  to 
facial  harmony. 

The  second  division  is  ';  Complex  Irregularities,"  which 
must  include  all  cases  where  there  is  extensive  malposition  of 
the  teeth  or  jaws  and  corresponding  dento-facial  deformity. 


139 


DIVISION  I. 


FIG.  77. 


SIMPLE  IRREGULARITIES. 

Under  this  head  are  included  all  those  lesser  irregulari- 
ties in  which  but  few  teeth  are  involved  and  where  the 
operation  of  correction  is  confined  to  a  limited  area  with  no 
real  complications. 

Usually  these  simple  cases  present  during  the  transi- 
tional stage  between  first  and  second  dentition.  As  already 
stated  in  Part  I,  Chapter  2,  the  trouble  may  begin  with  the 
eruption  of  the  first  permanent  molar  if  any  of  the  decidu- 
ous molars  have  been  prematurely  lost  or  if  their  forms 
have  been  materially  altered  through  extensive  caries.  In 
the  act  of  eruption  this  tooth  is  compelled  to  take  a  posi- 
tion close  to  and  behind  the  deciduous  teeth,  and  if  this 

position  be  anterior  to 
normal  the  space  for 
the  later  erupting  teeth 
will  be  lessened  and 
irregularity  be  sure  to 
follow.  This  irregu- 
larity will  usually  be 
most  noticeable  in  the 
partial  closure  of  the 
cuspid  space  with  the 
result  of  forcing  that 
tooth  to  erupt  in  mal- 
position. 

Again,  the  premature 
loss  of  the  anterior  deciduous  teeth  or  indeed  any  of  the 
deciduous  set  will  result  in  a  diminished  size  of  the  arch  and 
if  the  opposite  arch  be  of  normal  size  a  disparity  is  at  once 
produced. 

140 


Beginning  of  Malocclusion    (Knapp).. 


SIMPLE    IRREGULARITIES.  141 

Fig.  77  shows  such  a  result  where  the  normal  enlargement 
of  the  upper  arch  has  been  interfered  with,  while  the  lower 
has  developed  naturally. 

Nearly,  if  not  all  cases  of  protrusion  and  retrusion,  have 
had  their  foundations  laid  in  this  way. 

So,  too,  the  overlapping  of  incisors  or  their  torsion  usually 
occurs  at  the  time  of  their  eruption  and  while  the  causes 
for  these  conditions  may  not  be  apparent  the  necessity  for 
immediate  interference  is  imperative. 

Unfortunately  we  do  not  have  the  oversight  of  our  future 
patients  as  early  as  we  should.  If  we  had,  probably  three- 
fourths  of  the  cases  of  irregularity  that  we  are  called  upon 
to  treat  would  have  been  prevented,  for  close  observation 
during  the  period  of  eruption  would  enable  us  to  forestall 
any  serious  malposition.  The  guiding  of  the  new  teeth 
into  their  normal  positions  could  be  accomplished  with  little 
difficulty  if  children  were  placed  under  supervision  of  the 
orthodontist  at  a  very  early  age. 

As  such  a  privilege  is  not  granted  us  our  main  efforts 
usually  have  to  be  directed  toward  the  correction  of  irregu- 
larities after  they  have  occurred. 


CHAPTER  I. 

LABIAL  OR  LINGUAL  MALPOSITION. 

Normally  the  permanent  lower  incisors  erupt  lingually  to 
the  deciduous  ones,  while  the  permanent  upper  incisors  erupt 
labially  to  their  deciduous  predecessors.  From  the  limited 
space  allotted  them,  there  is  a  stronger  tendency  to  irregu- 
larity on  the  part  of  the  lower  incisors  than  there  is  on  the 
part  of  the  more  favorably  located  upper  ones,  although  the 
latter  are  also  often  found  in  a  crowded  condition,  sometimes 
complicated  with  torsion. 

So  long  as  the  lower  ones  erupt  lingually,  even  though 
irregularly  arranged,  they  will  need  little  attention  on  our 
part  until  dentition  is  well  advanced,  when  it  will  generally 
be  found  that  nature  has  almost,  if  not  entirely,  corrected 
the  condition. 

So  also,  where  some  of  the  upper  incisors  erupt  slightly 
outside  of  the  normal  arch  line  with  spaces  between  them, 
we  need  not  interfere,  for  in  most  cases  the  force  exerted  by 
the  lips  and  the  erupting  cuspids  will  bring  them  into 
normal  position  and  relationship. 

Not  unfrequently,  however,  it  happens  that  from  some 
cause  an  upper  incisor  is  deflected  and  erupts  lingually,  or 
that  a  lower  incisor  is  found  to  erupt  labially.  In  either  case, 
treatment  is  indicated  as  soon  as  the  irregular  tooth  or  teeth 
are  sufficiently  erupted  to  enable  us  to  bring  the  proper 
force  to  bear  upon  them. 

In  the  great  majority  of  cases  of  this  character  there  is  not 
sufficient  space  in  the  arch  to  accommodate  the  malposed 
tooth  owing  to  the  moving  together  of  the  adjoining  ones. 

Such  being  the  case  our  efforts  will  have  to  be  directed  to 
creating  space  before  we  undertake  to  correct  the  irregu- 
larity. 

142 


LABIAL    OR    LINGUAL    MALPOSITION. 


143 


FIG.  78. 


One  plan  of  doing  so  is  shown  in  Fig.  78. 

The  appliance  consists  of  bands  fitted  to  the  two  teeth 
adjoining  the  space  and  a  curved  piano  wire  spring  operat- 
ing between  them. 

The  ends  of  the  spring  fit  into  holes  drilled  in  the  bands. 
Before  inserting  the  spring  its  two  arms  are  drawn  nearly 
together  with 
brass  ligature 
wire  and  this, 
upon  being 
gradually  re- 
leased, allows 
the  spring  to 
open  until  the 
ends  find  their 
places  in  the 


in 

holes     in 
bands. 


the 


Increasing  Space  by  Curved  Spring  and  Bands. 

Another  method  is  that  of  Professor  Goddard,  shown  in 
Fig.  79.  Describing  it  he  said  :  "  The  two  teeth  bordering 
the  space  are  encircled  by  bands  having  short  open  tubes 
soldered  to  their  labial  surfaces  in  a  horizontal  position. 
Through  these  tubes  is  passed  a  threaded  wire  having  two 
nuts  upon  it.  One  of  these 
is  designed  simply  to  offer 
resistance,  while  the  other, 
by  being  turned,  will  gradu- 
ally force  the  teeth  apart." 


FIG.  79. 


If  preferred,  the  same 
result  may  often  be  accom- 
plished by  the  use  of  the 
compressed  wooden  wedge 
shown  in  Fig.  36. 

In  many,  perhaps  in  most  cases  of  insufficiency  of  space 
the  enlargement  of  the  whole  or  at  least  the  anterior  portion 
of  the  arch  is  called  for,  not  only  to  provide  room  for  the 


Appliance  for  Separation  (Goddard). 


144  ORTHODONTIA. 

malposed  teeth,  but  especially  to  give  to  it  the  size  and  form 
required  for  the  normal  occlusion  of  the  upper  teeth  with 
those  in  the  opposite  jaw. 

This  is  accomplished  in  nearly  all  cases  by  some  form  of 
an  expansion  arch  or  bow  wire  with  the  accessory  wire  liga- 
tures, as  shown  in  illustrations  in  Part  III,  Division  II. 

Space  having  been  provided,  there  are  three  ways  in 
which  we  may  exert  force  advantageously  for  the  labial  or 
lingual  movement  of  incisor  teeth. 

They  are:  the  inclined  plane;  the  elasticity  of  spring 
wire ;  and  the  screw  in  its  various  forms. 

The  Inclined  Plane. — This  was  one  of  the  earliest  methods 
employed  for  releasing  an  inlocked  upper  incisor,  and  was 
generally  designated  the  "  saddle  and  inclined  plane." 
Although  crude  in  design  and  scarcely  scientific  in  its 
operation,  it  nevertheless  served  a  useful  purpose  in  its  day, 
and  may  even  now  be  employed  in  rare,  special  cases  with 
good  results. 

Its  earlier  form  is  shown  in  Fig.  80.  The  saddle  was 
usually  formed  of  metal,  swaged  to  fit  and  cover  all  of  the 
lower  incisor  teeth.  To  this,  at  some 
point  of  the  ridge,  was  soldered  an  inclined 
piece  of  heavy  metal  so  arranged  that  the 
inlocked  tooth  would  strike  upon  it  in  mas- 
incimed  Plane.  tication  and  be  forced  outward  into  line. 

Later  the  appliance  was  often  made  of  vulcanite,  and 
while  in  either  form  it  generally  answered  the  purpose  of 
correcting  the  simple  irregularity,  it  was  objectionable  on 
account  of  its  size  and  because  it  was  removable  and  thus 
liable  to  be  lost  or  laid  aside  and  not  worn. 

A  modification  of  and  improvement  upon  the  old  form, 
retaining  its  virtues  and  obviating  its  disadvantages,  was 
devised  by  the  author  many  years  ago.  By  its  use,  when 
attached  to  a  single  tooth,  a  double  movement  is  produced, 
for  while  by  the  action  of  the  plane  the  superior  inlocked 
tooth  is  moved  outward,  the  lower  outstanding  one,  to 
which  the  plane  is  attached,  is  moved  inward. 


LABIAL    OR    LINGUAL    MALPOSITION.  145 

When  it  is  not  desired  to  move  the  lower  tooth  it  can  be 
prevented  by  making  the  appliance  include  two  or  more 
teeth  and  thus  offer  more  resistance. 

It  is  constructed  as  follows:  A  band  of  thin  platinum, 
gold  or  German  silver  plate  (No.  29,  B.  and  S.  gauge)  is  bent 
to  encircle  and  fit  the  protruding  lower  incisor,  and  the  ends 
soldered.  A  piece  of  ordinary  gold  plate  is  then  bent  double 
to  form  an  inclined  plane,  and  spread  apart  at  its  ends  to 
grasp  the  band  on  the  lingual  and  labial  surfaces,  to  which 
it  is  soldered.  It  is  next  placed  upon  the  tooth  to  see  that 
the  adjustment  is  correct,  removed,  lined  with  zinc  phos- 
phate, and  pressed  permanently  into  position.  If  the  teeth 
are  in  close  contact  it  is  well  to  allow  the  fixture  to  be  worn 
a  few  hours  previous  to  cementing,  for  then  the  teeth  will 
have  been  pressed  apart  and  the  replacement  with  cement 
will  be  more  easily  accomplished.  The  cement  not  only 
lines  the  band,  but  fills  all  the  space  between  the  inclined 
plane  and  the  tooth,  thus  giving  greater  resistance  and 
strength  in  biting.  It  is  shown  in  position  and  F 
separately,  in  Fig.  81.  Its  advantages  are  its 
small  size  and  absolute  fixedness.  When  the 
correction  has  been  accomplished,  it  will  be 
necessary  to  cut  the  band  in  order  to  remove  it. 
Two  objections  have  been  urged  against  the  em- 
ployment of  inclined  planes  in  any  form:  one,  Fixed pis 
that  by  thus  opening  the  bite,  the  posterior  teeth  will  elon- 
gate; the  other,  that  the  patient  may  avoid  biting  upon 
the  plane  and  thus  defeat  our  object.  These  objections 
have  no  real  validity,  as  is  shown  by  actual  experience. 

The  short  time  that  the  bite  is  open,  usually  only  a  week 
or  two,  is  not  long  enough  to  permit  of  any  perceptible 
elongation,  while  the  patient  must  and  does  bite  upon  the 
plane  in  mastication,  because  it  is  the  only  point  where 
occlusion  is  possible. 

Wire  Springs. — Of  greater  value  in  the  labial  movement 
of  one  or  more  upper  or  lower  incisor  teeth  is  a  spring  wire 
applied  in  some  of  the  many  ways  of  which  it  is  capable. 


146 


ORTHODONTIA. 


FIG. 


Fig.  82  illustrates  a  simple  and  effective  appliance  for 
moving  labially  an  upper  central  which  had  erupted  lin- 
gually.  The  first  deciduous  and  first  permanent  molars 
were  banded  and  then  joined  on  their  lingual  surfaces  by  a 

piece  of  round 
tubing  closed  at  its 
distal  end.  The 
incisor  was  fitted 
with  a  platinum 
band  to  which 
was  soldered  a  U- 
shaped  lug  on  its 
lingual  surface. 
By  inserting  a 

Tube,  Band  and  Spring  Appliance  (Matteson).  piece  of  fine  piano 

wire  into  the  tube  and  springing  its  free  end  into  the  incisor 
lug  the  elasticity  of  the  wire  forced  the  tooth  into  position  in 
a  few  days'  time. 

Where  both  upper  laterals  are  inlocked  they  may  be 
moved  labially  into  line  by  means  of  a  Coffin  plate  and 

suitably  shaped  extension 
wires,  as  shown  in  Fig.  83. 
The  vulcanite  plate  is 
made  to  cover  the  palate 
and  enclose  several  bicus- 
pids or  molars  on  each 
side.  In  each  of  the  buccal 
portions  of  the  plate  a 
piece  of  piano-wire  is  im- 
bedded, which  extends 
forward  clear  of  the  teeth 
and  terminates  in  a  curve 
or  hook  opposite  the  tooth  to  be  moved  outward.  A  section 
of  rubber  tubing  is  slipped  over  the  tooth  and  caught  upon 
the  hook.  The  elasticity  of  the  rubber  added  to  the  spring 
of  the  metal  will  rapidly  draw  the  tooth  outward  provided 
there  is  sufficient  space  in  the  arch  to  accommodate  it. 


FIG.  83. 


LABIAL    OR    LINGUAL    MALPOSITION. 


147 


FIG.  84. 


Moving  Laterals  Labially. 


Where  the  centrals  are  in  proper  position  and  the  laterals 
are  ins  ide  of  therch,  the  former  may  be  made  to  offer  the 
resistance  necessary  for  bringing  the  latter  into  alignment. 

Magill  bands  are  fitted  to  the  centrals,  and  a  bar  of  half- 
round  platinous  gold  is  soldered  to  these  on  their  labial 
surfaces  extending  a  little  beyond 
the  region  of  the  laterals.  When 
the  appliance  is  cemented  to  the 
centrals  each  lateral  is  ligated  to 
the  bar,  which  by  its  elasticity  will 
cause  these  teeth  to  move  outward. 

Fig.  84  represents  the  device  in 
position. 

When  the  laterals  are  situated  outside  of  the  arch  line  a 
similar  appliance  is  made  with  the  extensions  of  the  bar 
resting  upon  the  laterals,  as  shown  in  Fig.  85. 

Pieces  of  elastic  rubber  inserted  between  the  bar  and  the 
laterals  will  gradually  force  them  into  place. 

If,  in  the  act  of  moving  the  laterals  inward  the  centrals 
should  be  moved  slightly  outward,  the  latter  will  usually 
fall  back  into  their  former  positions  at  the  close  of  the 
operation. 

Frequently  a  better  curve  of  the  arch  is  produced  by  mov- 
ing the  centrals  outward  and  the  laterals  inward. 

For  retaining  the  moved  teeth  in  their   new   positions 
nothing  is  more  effective  and 
simple  than  a  retainer  construc- 
ted   on   the  "  band    and    bar " 
principle,  as  shown  in  Fig.  70 

Another  way  of  moving  in- 
locked    laterals    OUtward     is    to  Labial  and  Lingual  Movement. 

solder  one  end  of  a  platinous  gold  bar  to  a  platinum 
band  made  to  encircle  one  of  the  laterals  and  attached  to  it 
by  zinc  cement.  Arranged  in  this  way,  the  bar  has  but  one 
free  end,  which  is  more  readily  ligated  to  the  other  lateral. 
Fig.  86  illustrates  an  appliance  of  this  character,  which 
was  used  to  bring  out  into  position  two  superior  laterals  in 


FIG.  85. 


148 


ORTHODONTIA. 


FIG.  86. 


Spring  Bar. 


the  mouth  of  a  girl  ten  years  of  age.  The  case  was  compli- 
cated by  one  of  the  centrals  being  slightly  turned  upon  its 
axis. 

A  platinum  band   or  collar   was  made  to  fit  the  right 

lateral,  and  to  its  labial  sur- 
face was  soldered  one  end  of 
a  bar  of  spring  gold,  long 
enough  to  extend  over  the 
centrals  and  cover  the  oppo- 
site lateral.  The  bar  was 
converted  into  a  hook  at  its 
free  end  and  so  shaped  that 
in  its  course  it  touched  only 
the  prominent  edge  of  the 
turned  central.  The  band  was  then  cemented  to  the  right 
lateral,  and  a  section  of  small  rubber  tubing  passed  under 
the  left  lateral  and  caught  in  the  hook.  The  appliance 
thus  operated  in  two  ways :  First,  to  bring  the  laterals  out 
into  line  and  next  to  press  backward  and  inward  the 
protruding  corner  of  the  central. 

Where  any  one  or  two  of  the   superior  incisors  are  in 

labial  malposition  and 

<IG.    87. 

there  is  a  space  for  their 
accommodation  in  the 
arch  they  can  very 
easily  be  moved  into 
place  by  means  of  a 
plate  as  shown  in  Fig.  87 
The  plate  is  of  vul- 
canite in  which  two 
piano-wire  springs  are 
imbedded.  These 
springs  are  arranged  to 
rest  and  bear  upon  the  outstanding  teeth  and  may  be  bent 
from  time  to  time  to  increase  the  tension. 

In  the  lower  arch  the  irregularity  in  most  cases  is  con- 
fined to  one  or  two  of  the  incisors  in  either  labial  or  lingual 


Vulcanite  Plate  with  Piano-Wire  Springs 


LABIAL    OR    LINGUAL    MALPOSITION. 


149 


FtG. 


Coffin  Plate  for  Lower  Incisors. 

most   satisfactory  means  of 


malposition.  If  located  lingually  they  may  be  forced  into 
place  by  means  of  a  Coffin  plate,  constructed  as  shown  in 
Pig.  88. 

Should  the  piano-wire 
springs  show  a  tendency  to 
slip  toward  the  incisal  edges, 
bands  with  lugs  may  be 
cemented  to  the  teeth  to  be 
moved  and  the  ends  of  the 
springs  placed  in  the  lugs. 

The  Screw. — In  cases  which 
admit  of  its  employment  the 
screw  furnishes  the  best  and 
applying  power  in  the  moving  of  teeth,  singly  or  en  masse, 
in  either  the  upper  or  lower  arches. 

For  its  operation  it  usually  requires  a  more  elaborate  and 
possibly  a  less  comfortable  piece  of  mechanism  than  the 
inclined  plane  or  the  spring,  but  it  possesses  the  advantage 
of  accurately  control- 
ling movement  and 
enabling  the  patient  to 
assist  in  the  operation. 

Fig.  89  illustrates  a 
device  for  moving 
labially  the  two  upper 
central  incisors.  Bands 
with  lugs  on  their 
lingual  surfaces  are 
cemented  to  the  teeth  to 
be  moved.  To  the  first 
molars  clamp  bands  are 
attached,  haying  tubes 
soldered  to  their  lingual  portions.  An  arch  wire,  with 
threaded  ends  and  nuts,  is  inserted  into  the  tubes  and  placed  in 
the  incisor  lugs.  The  nuts  operate  against  the  anterior  ends 
of  the  tubes  and  by  their  action  force  the  incisors  into  line. 


FIG.  89. 


Moving  Incisors  Labially  (Knapp). 


150 


ORTHODONTIA. 


FIG.   90 


Fig.  90  shows  a  somewhat  similar  appliance  except  that 
the  tube  is  attached  to  two  bands  on  each  side  thus  afford- 
ing increased 
anchorage. 

The  same  meth- 
od can  be  followed 
in  moving  any  of 
the  lower  incisors 
labially  as  illus- 
trated in  Fig.  91. 

While  all  of 
these  appliances 
are  placed  on  the 
inside  of  the  arch, 
and  thus  in  a 

•i«^"i™^B™» 

Moving  Centrals  Labially.  measure        are 

concealed,  they  have  the  disadvantage  of  interfering 
somewhat  with  the  movements  of  the  tongue.  This  will 

naturally  suggest  the 
necessity  for  avoiding  any 
rough  edges  or  ragged 
screw  ends  which  would  be 
likely  to  irritate  the  soft 
tissues. 

An  arch  or  bow-wire 
may  be  made  to  extend 
around  the  outside  of  the 
arch  instead  of  the  inside 
and  the  movement  of  the 

Moving  Lower  Incisors  Labially  (Knapp.)      teeth  be  brought  about  by 

ligating  them  to  the  wire.  Many  prefer  this  latter  method, 
but  it  does  not  apply  the  force  in  as  direct  a  manner  as  the 
inside  wire  and  is  withal  more  conspicuous. 


FIG.  91. 


CHAPTER  II. 

MESIAL  AND  DISTAL  MALPOSITION. 

The  moving  of  teeth  forward  or  backward  in  the  line 
of  the  arch  is  not  a  difficult  procedure  provided  space  exists 
for  their  accommodation  in  the  new  position. 

Such  space  may  be  present  if  a  tooth  has  been  extracted. 
If  recently  extracted  there  will  be  but  a  thin  alveolar  wall 
to  be  broken  down  through  resorption,  and  but  little  force 
will  be  required  to  accomplish  it. 

If  considerable  time  has  elapsed  since  extraction  the  for- 
mer alveolus  will  have  [been  filled  up  with  new  calcic 
material  and  its  resistance  to  pressure  will  consequently  be 
greater.  If  a  number  of  teeth  are  to  be  moved,  either 
mesially  or  distally  in  phalanx,  the  difficulties  will  be  corres- 
pondingly increased. 

It  will  thus  be  seen  that  the  difficulty  or  ease  of  forward 
or  backward  movement  of  teeth  is  entirely  dependent  upon 
the  amount  of  resistance  to  be  overcome,  and  that  in  cases 
of  greater  difficulty  more  force  will  have  to  be  applied  to 
accomplish  the  result.  The  surprising  rapidity  with  which 
teeth  sometimes  move  either  mesially  or  distally  is  accounted 
for  by  the  fortunate  fact  that  the  alveolar  septa  do  not  have 
any  cortical  covering,  but  are  composed  entirely  of  cancel- 
lous  bony  material. 

As  in  all  other  cases,  however,  teeth  with  long  single 
roots,  like  the  cuspids,  or  those  with  several  roots  like  the 
molars,  will  offer  greater  resistance  to  applied  force  than  the 
incisors  or  bicuspids. 

Therefore,  in  undertaking  the  mesial  or  distal  movement 
of  teeth,  our  choice  of  methods  must  be  determined  by  the 
existing  conditions.  The  simplest  method  of  applying  force, 
and  usually  the  slowest  in  producing  results,  is  the  use  of 

151 


152 


ORTHODONTIA. 


FlG.   92. 


rubber  rings  operating  between  a  band  placed  upon  the 
tooth  to  be  moved  and  one  upon  the  anchor  tooth,  as  shown 
in  Fig.  92. 

The  anterior  bands  should   have  hooks  (bent  forward) 

soldered  to  the  labial  and 
lingual  surfaces,  while  the 
band  on  the  anchor  tooth 
should  be  provided  with 
similar  hooks  bent  back- 
ward. 

Two  rubber  rings, 
caught  over  the  hooks, 
connect  the  two  hands  and 
yield  the  tractile  power 
required.  These  rubber 
Appliance  for  Retraction.  rings  can  be  removed  and 

replaced  for  cleansing  the  teeth,  or  can  be  renewed  at  will 
by  the  patient.  Two  rings  can  be  attached  to  each  pair  of 
hooks,  if  greater  power  be  required,  or  the  same  object  can 

be   attained    by  cutting   wider 
rings  from  thicker  tubing. 

While  the  tractile  force  of  the 
rubber  is  not  very  great,  it  is 
often  sufficient  to  move  teeth 
not  too  firmly  implanted.  In 
nearly  all  cases,  however,  it  will 
be  found  better  to  employ  the 
positive  and  greater  force  of  the 
screw,  since  it  is  more  easily 
regulated  and  controlled. 

Fig.  93  illustrates  the  gener- 
ally preferred  method  for 
moving  distally  a  cuspid  tooth. 
Two  molar  bands  are  joined  by  solder,  and  these  again  are 
united  to  a  tube  extending  along  their  buccal  surfaces. 
The  band  on  the  cuspid  is  fitted  with  a'  short  tube  set 


FIG.  93. 


Distal  Movement  of  Cuspid. 


MESIAL    OR    DISTAL    MALPOSITION 


153 


FIG.  94. 


Distal  Movement  of  Cuspid  ( Canning ). 


vertically.  The  traction  wire,  bent  at  right  angles  at  one 
end  to  engage  with  the  tube  on  cuspid  band,  extends  back 
through  the  molar  tube ;  about  one-half  inch  of  its  distal 

o 

end  is  threaded 
and  provided  with 
a  nut.  The  turn- 
ing of  the  nut  once 
or  twice  daily  by 
the  patient  will  suf- 
fice to  move  even 
as  obstinate  a  tooth 
as  the  cuspid  in  a 
very  little  while. 

Fig.  94  shows  a 
somewhat  similar 
device  employing 
a  straight  traction 
wire  with  ball  end  passing  through  a  horizontal  tube  on 
cuspid  band.  Between  the  nut  at  the  distal  end  and  the 
molar  tube  there  is  a  coiled  wire  spring  which  keeps  a 
continuous  tension  on  FIG.  95. 

the  malposed  tooth. 

The  originator,  Mr. 
Canning,  claims  for  this 
appliance  the  combined 
advantages  of  the  spring 
and  screw.  Where  two 
teeth  on  opposite  sides 
of  the  arch  are  to  be 
moved  distally  at  the 
same  time  it  can  be 
accomplished  by  two 

SUch     devices      as     have       Distal  Movement  of  Lower  Cuspids  (Knapp). 

just  been  described,  or  by  a  threaded  bow  wire  passing 
through  horizontal  tubes  on  the  teeth  to  be  moved  and  the 
anchor  teeth,  as  shown  in  Fig.  95.  Nuts  at  the  rear  of  the 
molar  tubes  serve  to  draw  the  anterior  teeth  backward,  while 


154 


ORTHODONTIA. 


FIG.   96. 


anterior  nuts  operate  to  move  them  laterally  at  the  same 
time. 

In  the  upper  arch  the  cuspids  are  oftener  out  of  position 
than  any  of  the  other  teeth,  and  as  their  resistance  to  move- 
ment is  great,  owing  to  their  long  roots, 
the  resistance  of  the  anchorage  must  be 
correspondingly  greater.  Therefore,  in 
establishing  an  anchorage  it  should  be 
located  as  far  back  in  the  arch  as  possible 
and  be  made  to  include  two  teeth  at  least. 
These  two  teeth  should  be  banded  and 
the  bands  united.  The  banding  of  but 
one  tooth  on  a  side,  as  shown  in  the  last 
two  illustrations,  is  not  likely  to  be 
sufficient  to  resist  the  strain  when  exerted 
in  an  anterior  direction. 
When  the  strain  on  the  anchor  tooth  is  in  a  posterior 
direction  the  banding  of  a  single  tooth  will  suffice,  as  shown 

in  Fig.  96.  In  this  iii- 
was  desired  to- 
first  bicuspid 


Mesial  Movement 
of  Bicuspid   (Knapp). 


FIG.  97. 


stance   it 
move     a 

mesially  to  afford  oppor- 
tunity for  the  complete 
eruption  of  the  second 
bicuspid. 

The  anchor  band  on  the 
molar  was  a  clamp  band,  of 
the  Knapp  pattern,  with 
an  unusually  long  screw, 
which  passed  through  the 
tube  on  the  bicuspid  band. 
A  nut  operating  against 

the  distal  end  of  the  tube  pressed  the  two  banded  teeth  apart. 
When  space  is  to  be  provided  on  one  side  only  for  a  cuspid 

and  the  anterior  teeth  on  that  side  will  admit  of  a  labial 

movement,  all  may  be  accomplished  by  the  Knapp  device 

shown  in  Fig.  97. 


Unilateral  Mesial  Movement  (Knapp). 


MESIAL    OR    DISTAL    MALPOSITION 


155 


FIG.  98. 


The  right  lateral  and  left  cuspid  were  banded  and  con- 
nected by  a  wire  passing  around  and  touching  each  of  the 
incisors  upon  its  lingual  surface.  .A  screw  attached  to  the 
molar  anchor  band  operated  in  a  short  tube  or  pipe  soldered 
to  the  lateral  band,  on  the  ball  and  socket  principle.  As 
will  be  noticed  in  the  illustration,  the  banded  cuspid  served 
as  a  fulcrum,  the  screw  as  the  power  and  the  lateral  as  the 
resistance,  so  that  while  the  lateral  moved  the  greatest  dis- 
tance under  applied  force,  each  of  the  other  incisors  moved 
less  in  turn,  and  the  cuspid  not  at  all. 

Certainly  a  very  sci- 
entific and  effective  de- 
vice. 

Where  insufficient 
anchorage  exists  for 
moving  a  cuspid  dis- 
tally,  as  where  only  a 
single  molar  is  avail- 
able, this  slight  anchor- 
age can  be  supplement- 
ed to  advantage  by  em- 
ploying the  wire  arch 
and  head  cap,  as  illus- 
trated in  Fig.  98. 

The  tremendous  force 
exerted  by  the  elastics 
attached  to  the  protrusion  bow  will  often  be  sufficient  to 
move  distally  several  teeth  at  a  time,  and  thus  carry  the 
case  along  more  rapidly. 

An  abnormal  separation  of  some  of  the  upper  incisors  is 
often  met  with,  most  frequently  between  the  centrals. 

To  close  this  space  the  separated  teeth  must  be  drawn 
together.  A  rubber  band  would  furnish  enough  force  to 
accomplish  this,  but  it  should  only  be  used  when  it  can  be 
slipped  over  hooks  attached  to  the  labial  surfaces  of  bands 
cemented  to  the  malposed  teeth.  To  apply  it  to  the  bare 


Unilateral  Distal  Movement  (Knapp). 


156 


ORTHODONTIA. 


FIG.  99. 


teeth,  even  though  ligated  to  them,  is  extremely  dangerous 

on  account  of  its  liability  to  slip  up  and  irritate  the  gum 

tissue. 

The  author  has  seen  several  cases  in  which  disastrous 

results  have  followed  this  method,  in  some  instances  caus- 
ing extreme  extru- 
sion of  the  teeth  to 
which  it  was  applied. 
Fig.  99  shows  the 
author's  method  of 
dealing  with  cases  of 
anterior  separation. 

If  the  space  exist 
between  the  centrals, 
after  they  are  drawn 
together  the  laterals 
will  ha  veto  be  moved 
forward  to  support 
the  centrals.  It  is, 
therefore,  easier  and 
better  to  move  all 
four  at  once  by  band- 
ing the  laterals,  at- 
taching horizontal 

Mesial  Movement  of  Incisors. 

tubes    to   the    bands 

and  connecting  them  with  a  curved  screw  wire  as  shown  in 
the  illustration.  Nuts  operating  on  the  distal  ends  of  the 
wire  quickly  draw  the  teeth  together. 

To  retain  them  until  they  become  fixed  in  their  new 
positions,  lateral  bands  should  be  fitted  and  joined  together 
by  a  fine  platinous  gold  wire  following  the  line  of  the  previ- 
ous screw-wire. 


CHAPTER   III. 

EXTRUSION   AND   INTRUSION. 

In  orthodontia,  the  term  Extrusion  denotes  the  act  of 
thrusting  or  drawing  a  tooth  partly  out  of  its  alveolus, 
while  Intrusion  signifies  the  pushing  or  forcing  of  a  tooth 
deeper  into  its  socket.  The  two  movements  are  exactly 
opposite  in  character.  When  a  tooth  is  found  to  be  extruded 
\ve  restore  it  to  its  former  position  by  the  act  of  intrusion, 
while  a  tooth  that  has  been  intruded  is  brought  down  into 
place  by  the  act  of  extrusion. 

In  the  process  of  eruption,  each  tooth,  under  normal  con- 
ditions, will  emerge  until  its  crown  projects  beyond  the  free 
margin  of  the  gum  and  its  cutting  edge  or  occlusal  surface 
is  in  proper  relation  with  the  same  surfaces  of  the  adjoining 
teeth,  in  other  words,  in  the  line  of  occlusion. 

Extrusion. — Teeth  which  have  not  erupted  to  their  full 
extent  and  have  been  prevented  from  doing  so  by  the  too 
close  proximit}7  of  adjoining  teeth  or  other  cause,  may  be 
assisted  in  assuming  their  proper  alignment.  Where  space 
exists,  teeth  will  naturally  accomplish  their  full  eruption 
unaided.  When  they  do  not,  and  there  is  no  visible  cause 
for  their  not  doing  so,  we  may  safely  infer  that  some  hin- 
drance exists  in  the  tissues  beneath  the  gum.  It  may  only 
be  an  unexplainable  suspension  of  the  act  of  eruption,  or  it 
may  be,  and  often  is,  a  curvature  or  enlargement  of  the  root 
that  prevents  the  further  progress  of  the  tooth.  Which  of 
the  two  it  is,  can  usually  be  decided  by  an  X-ray  examina- 
tion. 

Where  full  eruption  of  a  tooth  has  been  made  impossible 
by  the  impingement  of  adjoining  teeth  upon  the  space 
intended  for  it,  increase  of  space  by  lateral  pressure  irpon  the 
interfering  teeth  should  first  be  gained  before  any  attempt 
is  made  at  extrusion.  Methods  for  doing  this  have  been 
given  in  a  preceding  chapter.  ' 

(157) 


158 


ORTHODONTIA. 


FIG.  100. 


Extrusion  (Goddard). 


Space  having  been  provided,  the  forcing  of  the  tooth  down 
into  line  may  be  accomplished  by  a  variety  of  methods.  In 
this,  as  in  all  other  cases  of  tooth  movement,  we  must 
have  a.  point  or  points  of  resistance  or  anchorage,  and 
then  a  suitable  means  of  applying  force  to  the  incompletely 
erupted  tooth.  For  obvious  reasons  the  resistance  should  be 
located  as  ,near  as  possible  to  the  tooth  to  be  moved  and  a 

safe  means  provided  for 
applying  the  required 
force. 

Both  of  these  condi- 
tions are  met  in  the  de- 
vice of  Prof.  Goddard 
shown  in  Fig.  100. 

It  consists  of  partial 
caps  of  gold  fitted  to  the 
two  adjoining  teeth  and 
connected  by  a  wire  soldered  to  them.  The  partially 
erupted  tooth  has  a  Magill  band  cemented  to  it,  and 
on  the  central  portion  of  this  band  on  both  labial  and 
lingual  sides  is  soldered  a  hook  or  pin.  After  the  connected 
caps  are  cemented  in  place  a  rubber  ring  is  caught  over  one 
hook,  passed  over  the  yoke,  and  caught  on  the  other  hook. 
If  the  incisal  edge  of  the  moving  tooth  is  in  direct  line 
with  the  wire  serving  as  resistance,  the  downward  move- 
ment will  be  checked  when  the  two  come  into  contact.  If 
they  should  not  be  in  line  there  would  be  great  danger  of 
the  tooth  becoming  unduly  extruded  through  the  continu- 
ous action  of  the  elastic  rubber  ring. 

Another  objection  to  this  particular  appliance  is  its  promi- 
nence and  possible  inter- 
ference with  speech  and 
mastication. 

To  obviate  these  unde- 
sirable features  the  author 
devised  the  appliance 

Author's  Appliance  for  Extrusion.  sllOWn  in   Fig.  101. 


FIG.  101. 


EXTRUSION    AND    INTRUSION.  159 

The  patient,  a  boy,  had  broken  off  the  mesio-incisal  corner 
of  his  superior  left  central.  Instead  of  trying  to  restore  the 
broken  portion  by  filling,  it  was  decided  to  draw  the  tooth 
down  and  grind  off  the  incisal  edge. 

To  do  this,  a  Magi.ll  band  was  snugly  fitted  to  the  right 
centra],  and  a  corresponding  band  (but  larger  than  the 
tooth)  was  soldered  to  it  at  its  periphery  to  surround  the  leftr 
central.  A  smaller  Magill  band  was  fitted  to  the  broken 
tooth  and  cemented  in  position  close  up  to  the  gum.  Each 
of  the  bands  surrounding  the  left  central  had  a  headed  tooth- 
pin  soldered  to  its  central  portion.  After  cementing  the 
single  band  in  place,  the  double  band  was  cemented  to  thje 
right  central  leaving  the  other  portion  of  it  free  to  pass/over 
the  left  central  with  a  space  between  the  band  and  the^tooth. 

The  pins  on  the  two  bands  were  now  connected  by  means 
of  platinum  binding  wire  with  the  ends  twisted  together. 
Tightening  the  twist  at  intervals  of  a  few  days  soon  brought 
the  tooth  down  below  its  fellows,  when  the  projecting  broken 
edge  was  dressed  to  a  proper  line  with  a  corundum  wheel. 

After  the  operation  was  completed,  the  appliance  was  kept 
in  place  for  a  month  as  a  retainer. 

While  wire  operates  much  more  slowly  than  rubber,  it  is 
very  much  safer  because  the  tooth  cannot  move  any  farther 
after  each  tightening  of  the  wire  than  in  response  to  the 
force  thus  exerted. 

As  a  tooth  will  move  out  of  its  socket  far  more  easily  and 
rapidly  than  in  any  other  direction  there  is  always  the 
•danger  of  applying  too  much  rather  than  too  little  force. 

The  greatest  difficulty  in  connection  with  cases  of  this 
character  is  that  of  holding  the  extruded  tooth  firmly  in 
position  until  sufficient  new  alveolar  tissue  has  been 
deposited  in  the  socket  to  prevent  subsequent  intrusion. 

The  simplest  and  best  retainer  is  that  shown  in  Fig.  71, 
and  in  most  cases  it  should  be  worn  for  a  period  of  six 
months  at  least. 

Intrusion. — This  operation  becomes  necessary  where  teeth 
have  been  extruded  either  through  the  impingement  of 


160  ORTHODONTIA. 

improperly  constructed  regulating  appliances  upon  the  gum 
or  the  unfortunate  misapplication  of  force  in  such  a  way  as 
to  lift  the  tooth  from  its  socket.     In  the  days  when  rubber 
FlG   102  bands  were   frequently 

employed  to  exert  force 
upon  teeth  to  move 
them,  and  were  not 
properly  secured  in 
place  upon  the  teeth, 
it  was  no  uncommon 

Device  for  Intrusion  (Goddard).  occurrence   for  them    to- 

slip  up  under  the  free  margin  of  the  gum  and  by  irritation 
cause  extrusion  of  the  teeth.  Since  the  introduction  of  the 
Magill  band  this  liability  has  almost  ceased. 

Teeth  never  become  extruded  except  through  disease, 
disuse  or  mechanical  influence. 

When  extrusion  is  of  recent  occurrence  and  is  the  result 
of  accident,  a  period  of  rest  will  usually  bring  about  the 
return  of  the  tooth  to  its  former  position,  or  nearly  so. 

Where,  however,  the  condition  has  continued  for  some 
time  new  bony  tissue  will  have  been  formed  in  the  space  in 
the  alveolus  caused  by  the  movement  of  the  tooth,  and  its 
return  to  its  former  position  will  be  a  matter  of  some  diffi- 
culty. In  certain  cases  it  may  be  brought  about  by  the 
Goddard  device  shown  in  Fig.  102.* 

It  consists  in  banding  a  tooth  on  each  side  of  the  one  to 
be  operated  upon  and  connecting  the  bands  by  wires  sol- 
FIG   103  dered  to  both  their  labial  and  lingual 

surfaces;  or,  as   shown  in   cut  103. 
soldering  the  wires  to  but  one  of  the 
bands,  and  allowing  their  free  ends 
Detail  of  construction.        to  rest  UpOn  hooks  attached  to  the 
other   band.     When   in    place,   a   slender    rubber   ring   is 
stretched  from  one  wire. to  the  other,  passing  in  its  course 
over  the  incisal  edge  of  the  extruded  tooth.     A  small  cap 

*  The  American  Text-Book  of  Operative  Dentistry,  p.  594. 


EXTRUSION    AND    INTRUSION. 


161 


FIG    104. 


with  a  notch  in  it  should  be  cemented  to  the  long  tooth  to 
keep  the  rubber  in  position. 

Fig.  103  shows  the  method  of  construction. 

While  the  elasticity  of  rubber  rings  is  fully  equal  to  the 
demands  of  extrusion,  something  more  powerful  is  needed 
in  intrusion. 

Metallic  springs  or  the  head  cap  and  protrusion  bow  are 
none  too  powerful,  especially  where  the  extrusion  is  not  of 
recent  occurrence  or  where  two  or  more  teeth  are  to  be 
intruded. 

An  ingenious  device,  designed  by  Prof.  Case  *  for  the 
double  purpose  of  intruding  the  incisors  and  extruding  the 
bicuspids,  is  shown  in  Fig.  104. 

In  describing  its  construction  he  says : — "  On  each  molar 
(first  or  second  according  to  the  age  of  the  patient)  is  placed 
a  hollow  metal 
crown  on  the 
buccal  surface  of 
which  is  solder- 
ed an  open  tube 
or  trough,  open- 
ing upward. 
On  each  bicus- 
pid is  cemented 
a  band  with  a 
buccal  hook 

pointing    down-  Intrusion  and  Extrusion  (Case). 

ward,  also  on  the  first  molar  if  the  second  has  been  used 
for  supporting  the  hollow  crown.  On  the  incisors  are 
cemented  bands  with  hooks  turned  upward.  A  labial  bow 
of  elastic  German  silver  or  piano-wire  has  its  ends  inserted 
in  the  troughs  of  the  hollow  crowns,  its  front  resting  above 
the  hooks  on  the  incisors,  and  its  sides  pressed  under  the 
hooks  on  the  bicuspids  and  first  molar.  The  action  is  such 
as  to  depress  the  incisors  and  elevate  the  bicuspids,  and,  if 
possible,  the  first  molars  also." 

*  Dental  Review,  December.  1985. 


162  ORTHODONTIA. 

Forcible  eruption  of  a  tooth  by  means  of  the  extracting 
forceps  is  seldom  justifiable,  for  we  cannot  always  know 
what  may  have  interfered  with  the  eruption.  In  certain 
exceptional  cases,  where  a  careful  examination  reveals  no 
sign  of  malformation  of  the  root  and  where  it  is  perfectly 
evident  that  slight  impingement  of  adjoining  teeth  has  been 
the  sole  hindrance  to  full  eruption,  the  forceps  may  prove  a 
valuable  means  of  effecting  a  rapid  and  easy  correction  of 
the  difficulty. 

Such  a  case  occurred  in  the  author's  practice.    The  patient 
was  a  gentleman  of  about  twenty-eight  years  of  age,  whose 
right  central  incisor  was  about  a  line  shorter  than  its  mate. 
It  had  been  tardy  in  erupting  and  in   consequence  there 
FlG  105  was  a  slight  lack  of  space  for 

its  accommodation,    as   shown 
in  Fig.  105. 

As  the  difference   in  length 
of  the   two    incisors    was    too 
incomplete  Eruption.  great   to   be   remedied   by  the 

simple  means  of  reducing  the  length  of  the  longer  one,  it 
was  decided  to  elongate  the  shorter  one.  A  careful 
examination  proving  favorable,  a  piece  of  sand  paper  was 
folded  so  as  to  cover  both  labial  and  lingual  surfaces  of 
the  tooth  to  protect  it  from  injury,  after  which  it  was 
grasped  with  the  forceps  and  by  a  combined  rotary  and 
downward  motion  brought  into  place.  Once  in  position 
it  was  held  there  by  the  pressure  of  the  adjoining  teeth, 
but  to  guard  against  possible  displacement  a  simple 
retaining  appliance  was  placed  upon  it. 


CHAPTER  IV. 

TORSION. 

In  a  dental  sense  the  terms  Torsion  and  Rotation  both 
signify  the  act  of  turning  a  tooth  upon  its  axis,  and  we  have 
no  word  in  the  English  language  to  describe  a  tooth  which 
is  in  a  turned  position. 

Therefore,  to  distinguish  between  the  act  and  the  condi- 
tion and  for  want  of  a  better  term  we  shall  employ  the  word 
Torsion  to  signify  the  condition,  and  Rotation  to  designate 
the  act  of  turning. 

Torsion  is  due  to  some  abnormal  influence  operative 
before  or  doing  eruption.  Lack  of  space  will  often  impel  a 
tooth  during  eruption  to  turn  in  such  a  way  as  to  present  its 
smaller  diameter  toward  the  space  intended  for  its  accom- 
modation, in  order  to  occupy  that  space  at  all.  A  root,  or 
even  a  portion  of  one,  will  also  often  cause  a  tooth  to  partly 
turn  in  its  socket  while  seeking  its  position  in  the  arch. 
Torsion  of  the  superior  central  incisors,  so  often  met  with,  is 
doubtless  due  in  the  majority  of  cases  to  undue  thickness  of 
the  median  alveolar  septum.  The  condition  is  also  pro- 
duced after  eruption  by  the  crowding  of  adjoining  teeth 
induced  by  some  unusual  pressure,  such  as  the  effort  of  a 
later  erupting  tooth  to  occupy  its  place  in  the  arch. 

Torsion  is  met  with  in  all  degrees  of  extent,  from  the 
slightest  prominence  of  one  corner  of  a  tooth  to  a  complete 
half-turn. 

It  occurs  generally  in  single-rooted  teeth  ;  and  those  with 
roots  most  nearly  round  are  the  ones  commonly  affected  on 
account  of  the  ease  with  which  they  can  be  made  to  turn 
upon  their  axes. 

At  times  cases  are  met  with  in  which  two  adjoining  teeth 
are  thus  affected,  usually  in  like  degree.  This  condition  is 
known  as  Double  Torsion  and  is  represented  in  Fig.  106. 

163 


164 


OIVTHODONTIA. 


FIG.   106. 


Double  Torsion. 


Rotation  is  usually  not  a  very  difficult  operation  in  itself, 
but  when  complicated  by  the  crowding  or  disarrangement 
of  adjoining  teeth  it  sometimes  proves  quite  troublesome. 

Where  there  is  sufficient  space  in  the  arch  to  accommo- 
date the  tooth  after  it  has  been  turned,  we  have  simply  the 

matter  of  rotation 
to  deal  with,  but 
when  such  is  not 
the  case,  our  first 
efforts  must  be 
directed  toward 
providing  space. 
This  may  be  done, 
if  the  deficiency  be 
slight,  by  pressing 
apart  the  impin- 
ging teeth  by  some 
of  the  means 
previously  described ;  but  where  great  space  needs  to  be 
provided,  expansion  of  the  arch  will  be  necessary  in  order  to 
afford  opportunity  for  bringing  the  turned  tooth  into  line. 
In  the  case  of  teeth  with  flat  crowns,  as  the  incisors,  we  may 
adopt  either  of  two  plans  for  turning  the  tooth,  viz. :  grasp- 
ing the  crown  throughout  its  entire  circumference  and 
applying  suitable  power,  or  by  direct  pressure  upon  one  or 
both  of  the  angles  that  are  out  of  line.  With  teeth  having 
round  crowns,  such  as  the  cuspids,  we  are  limited  to  the 
plan  of  making  attachment  to  the  periphery  of  the  crown. 
At  one  time  it  was  difficult,  if  not  almost  impossible,  to 
grasp  a  tooth  so  securely  as  to  have  the  attachment  resist 
the  strain  of  the  applied  force,  but  since  the  introduction  of 
the  Magill  band  this  greatest  of  all  difficulties  associated 
with  rotation  has  been  overcome. 

A  method,  commonly  employed  for  rotating  a  single  tooth, 
is  shown  in  Fig.  107.  It  consists  of  a  metal  band  made  to  fit 
the  tooth  to  be  rotated  and  having  an  extension  bar  of  half 


TORSION. 


165 


FIG.   107. 


Spring  Bar  and  Band  for  Rotation. 


round  platinous  gold    wire   soldered  to  its  labial  surface. 

The  free  end  of  the  bar  is  perforated  by  two  holes  for  liga- 

tion   to   some  firm  tooth,  usually  a  molar.     The  band  is 

cemented  to  the  tooth  and  the  bar  sprung  down  and  ligated 

to  the   tooth    selected  for 

anchorage.    The  immense 

pressure  of  this  bar  will 

quickly  compel  the  tooth 

to     turn    in     its    socket. 

As  its  force  becomes  spent 

from  time  to  time  the  bar 

can  be  bent  outward  with 

pliers  without  removing  it 

from  the  tooth.     After  the 

tOOth     has     been      brought 

into  proper  alignment,  it  is  most  conveniently  held  in 
position  by  means  of  the  retainer  shown  in  Fig.  69. 

Dr.  Angle  has  improved  this  appliance  by  making  the 
band  and  bar  detachable. 

The  band  is  fitted  with  a  section  of  German  silver  tubing 
soldered  to  its  labial  surface,  parallel  with  the  incisal  edge 
of  the  tooth.  Another  band,  with  a  hook  or  catch  soldered 
to  its  buccal  surface,  is  fitted  to  a 
bicuspid  or  molar.  This  latter  band 
also  has  a  piece  of  tubing  soldered 
horizontally  to  its  lingual  surface, 
through  which  is  passed  a  piece  of  i 
wire  intended  to  rest  against  the 
two  teeth  adjacent  to  the  one  banded 
and  thus  afford  greater  resistance. 
After  both  of  these  bands  are  cemen- 
ted to  their  respective  teeth,  a  Rotation  t  Angle). 

straight  piece  of  piano-wire  is  inserted  in  the  tube  of  the 
tooth  to  be  turned  and  bent  down  and  caught  in  the  catch 
on  the  anchor  tooth  as  shown  in  Fig.  108. 

The  advantage  of  this  modification  is,  that  a  weaker  or 


FIG.  108. 


166 


ORTHODONTIA. 


stronger  wire  can  be  substituted  at  will,  and  the  power  thus 
readily  be  controlled.  When  the  tooth  is  in  proper  line, 
the  wire  is  removed  and  replaced  by  a  shorter  one  resting 
upon  an  adjoining  tooth.  This  acts  as  a  retainer  by  keep- 
ing the  tooth  in  position  until  it  has  grown  firm.  The 
retaining  wire  is  secured  by  means  of  a  pin,  inserted  in  a 
hole  drilled  through  both  tube  and  wire. 

While  a  tooth  may  be  rotated  by  the  methods  just 
described,  they  are  not  truly  scientific,  because  the  spring  by 
its  force  will  throw  the  tooth  out  of  arch  alignment  at  the 
same  time  that  it  is  rotating  it. 

This  would  not  happen  if  the  tooth  were  simply  a  round 
object  with  a  firm  dowel  running  through  its  long  axis.  In 
that  case  the  dowel  would  serve  as  the  point  of  resistance 
around  which  the  object  would  be  obliged  to  rotate.  The 
tooth,  having  no  such  fixed  point  of  resistance  within  itself, 
is  free  to  move  away  from  its  socket  under  the  outward  force 
of  the  spring,  which  it  will  be  sure  to  do. 

This  is  clearly  illustrated  in  the  two  accompanying  figures 

reproduced     by    permission 
from  Dr.  Knapp's  book. 

"  In  Fig.  109,  let  A  repre- 
sent a  tooth  turned  upon  its 
*  axis.  To  place  this  tooth  in 
line  it  must  be  rotated  until 
it  is  in  the  position  B.  If  a 
circle  is  drawn  at  C  the 
mesial  and  distal  surfaces  of 
the  tooth  will  be  in  contact 
with  the  circle  at  the  points 
*D  D.  When  the  tooth  is 
being  properly  rotated,  the 
points  D  D  will  follow  the 

circumference  of  the  circle  to  the  points  E  E,  and  the  tooth 
will  be  in  the  position  B.  During  the  operation  the  center, 
F,  should  remain  unchanged.  Let  G  represent  a  piano-wire 


FIG.  109. 


TORSION. 


167 


spring  passed  through  a  tube  soldered  to  the  labial  surface 
of  the  band  on  the  tooth  A  and  anchored  to  any  tooth  in 
the  position  H.  The  direction  in  which  the  tooth  will  be 
moved  may  be  determined  by  permitting  the  spring  to  come 
to  a  position  of  rest  while  the  end  H  is  held  immovable. 
The  experiment  will  show  that  the  tooth  A  will  have  been 
moved  to  K  when  the  spring  is  at  rest,  which  is  a  most 
undesirable  position. 

If,  however,  two  forces  operate  in  opposite  directions  as 
shown  in  Fig.  110,  an  entirely  different  result  will  be 
obtained.  Let  L  and  M  represent  the  two  positions  of  the 
tooth  as  shown  at  A  and  B,  Fig.  109.  Let  R  represent  the 
anchor  tooth,  S  and  T  the  opposing  forces ;  S  connecting  the 
anchor  point  R  with  the  mesial  surface  of  the  tooth  and  T 
connecting  the  anchor  point,  R,  with  the  distal  surface  of 
the  tooth. 

If  these  two  forces  move  equally  in  opposite  directions  as 
indicated  by  the  arrows,  the  points  N  N  will  be  moved  to  O 
0,  while  the  center  or  axis  of  the  tooth,  F,  remains 
unchanged,  which  is  the  result  desired. 

Furthermore,  as  the  two  opposing  forces  unite  at  R  they  are 
equalized  and  no  strain  is  brought  to  bear  on  the  anchor  tooth. 

If  the  tooth  encircled  by  the  band  stood  in  such  position 
that  one  approximal  sur- 
face need  not  be  moved 
while  the  other  is  to  be 
drawn  in,  one  operating 
force  must  remain  station- 
ary, while  the  other  is 
contracted. 

Thus  it  will  be  seen  that 
by  the  employment  of  two 
jack-screws  a  tooth  may  be 
held  in  one  position  while  F1&- m-  Rotation  (KnaPP). 

it  is  being  rotated ;  one  side  of  the  tooth  may  be  held  and 
the  other  rotated ;  or  the  position  of  a  tooth  may  be  changed 
entirely  and  rotated  at  the  same  time." 


168 


ORTHODONTIA. 


FIG.   112. 


The  application  of  the  principle  just  elucidated,  of  exert- 
ing equal  and  opposing  forces  to  the  opposite  sides  of  a  tooth 
to  be  rotated,  is  illustrated  in  Fig.  Ill, 
where  a  right  central  incisor  is  being 
turned  in  its  socket. 

For  convenience  in  operating,  two 
teeth  have  been  banded  and  these  are 
connected  by  a  bar  to  which  the 
operating  screws  are  attached. 

Fig.  112  shows   the  same  principle 
applied  in  a  case  where  the  appliances 
can   be   confined    to   one  side   of    the 
mouth.     In  this  instance  but  one  band 
for   the   opposing  action  of 


Rotation  (Knapp).        js 
the  two  screws  couterbalance  one  another. 


FIG.  113. 


DOUBLE  TORSION. 

Where  two  adjoining  teeth,  as  the  superior  centrals,  are 
to  be  rotated  in  opposite  directions,  a  single  device  will  often 
accomplish  both  movements  at  the  same  time.  The  appli- 
ance devised  by  the  author  for  this  purpose  is  shown  in  Fig. 
113,  and  the  details  of  construction  in  Fig.  114. 

Two  narrow  strips  of  platinous  gold, 
No.  36,  are  bent  in  the  form  of  "  b  "  and 
"  c."  These  are  made  long  enough  to  be 
bent  slightly  over  the  labial  surfaces  of 
the  teeth  to  be  turned,  extend  along  the 
mesial  to  the  lingual  surface,  and  then 
along  this  latter  almost  to  the  distal  angle. 
After  being  properly  shaped  according  to 
the  model,  they  are  clamped  together  and 
soldered  along  their  contiguous  surfaces. 
Another  strip  of  platinous  gold  about 
an  eighth  of  an  inch  in  width,  and  gauge  No.  24  in  thick- 
ness, is  now  bent  to  conform  to  the  outline  that  we  wish  the 
turned  teeth  to  describe  when  in  normal  position.  Each 


The   Author's   Device 
for  Double  Rotation. 

FIG.  114. 


TORSION. 


169 


end  of  this  strip  is  bent  to  partly  encircle  the  disto-palatal 
angle  of  each  tooth  as  shown  at  "a,"  Fig.  114.  The  long 
arms  of  the  united  parts  "  b  "  and  "  c  "  are  bent  to  conform 
to  the  inner  surface  of  "a"  and  soldered  to  it,  after  which 
the  portion  passing  between  the  teeth  is  reduced  by  filing, 
so  as  to  occupy  as  little  space  as  possible. 

When  properly  constructed  the  labial  part  of  the  appli- 
ance will  rest  against  the  teeth  just  at  or  slightly  above  the 
most  prominent  points  of  their  convexity,  while  the  lingual 
portion  will  be  near  the  gum,  but  not  quite  touching  it,  and 
the  slightly  curved  ends  of  this  part  will  catch  just  above 
the  little  prominence  usually  found  at  the  disto-lingual 
angle  near  the  gum. 

Thus  made  and  placed,  the  piece  cannot  become  displaced 
by  the  lip  or  tongue,  except  when  loosened  by  the  moving 
of  the  teeth.  As  will  readily  be  seen,  by  its  use  force  is 
brought  to  bear  upon  four  points  of  the  two  teeth  at  one  time. 


FIG.  115. 


FIG.  116. 


Double  Torsion. 


Corrected  Case. 


A  valuable  feature  of  the  appliance,  had  in  view  in  its 
devising,  is  that  it  occupies  but  one  interdental  space  and 
thus  more  readily  favors  the  turning  of  teeth  that  are  more 
or  less  crowded. 

In  use,  the  patient  should  be  seen  each  day,  the  fixture 
removed  and  tightened  by  bending  the  long  arms  slightly 
toward  the  smaller  ones  and  sprung  into  place. 


170 


ORTHODONTIA. 


To  facilitate  its  introduction  in  the  first  instance,  a  piece 
of  rubber  may  be  placed  between  the  teeth  a  few  hours 
previous  to  the  insertion  of  the  appliance. 

To  guard  against  accidental  displacement  and  loss,  a  liga- 
FIG.  117.  FIG.  118. 


Torsion  of  Centrals,  with  Distal  Angles 
Pointing  Outward. 


Retaining  Plate  on  Corrected  Case. 


ture  should  be  tied  around  one  of  the  teeth,  passed  under 
the  front  bar  and  again  tied. 

Fig.  115  represents  a  case  of  double  torsion  which  was 
corrected  in  ten  days'  time  by  the  use  of  the  appliance  just 
described,  the  patient  being  seen  every  day ;  while  Fig.  11<> 
shows  the  completed  operation.  After  the  teeth  are  in  posi- 
tion, they  may  best  be  retained  by  means  of  the  retainer 
shown  in  Fig.  71. 

When  the  disto-incisal  angles  of  the  teeth  project  instead 
of  the  mesio-incisal,  the  appliance  described  is  rendered 
equally  serviceable  by  reversing  its  position  and  placing  the 

long  arm  on  the  labial  surface. 
Fig.  117  represents  a  case  of  this 
character,  while   Fig.  118  shows 
the  vulcanite  plate  with  gold  wire 
bow  that  was  used  to  retain  the 
teeth  after  correction.     A  simpler 
and   better  method  of    retention 
would  have  been  to  use  the  appliance  shown  in  Fig.  70. 
Dr.  Angle  has  devised  a  very  simple  and  effective  method 


FIG.  119. 


Rotating  Device  (Angle). 


TORSION. 


171 


FIG.  120. 


of  accomplishing  double  rotation  where  the  mesial  angles 
protrude.  Upon  each  of  the  teeth  to  be  rotated  he  places 
Magill  bands  with  tubes 
soldered  to  their  labial 
faces  near  the  distal  angles. 
One  tube  is  set  vertically 
and  the  other  horizontally. 
A  short  piece  of  piano  or 
German  silver  wire,  bent 
to  a  right  angle  at  one 
end,  is  inserted  into  these 
tubes  and  rotation  is  effec- 
ted by  the  elasticity  of 
the  wire. 

Two  views  of  the  appliance  are  shown  in  Figs.  119  and  120. 

Once  in  position,  the  teeth  are  retained  by  inserting  in  the 
tubes  a  suitably -shaped  piece  of  non-elastic  gold  wire. 


Rotating  Device  (Angle). 


DIVISION  II. 

COMPLEX   IRREGULARITIES. 

CLASS  I. 

Malposition  of  Anterior  Teeth.— Where  anterior  malposition, 
either  upper  or  lower,  involves  more  than  one  or  two  teeth 
with  lack  of  space  for  their  accommodation  the  condition  is 
no  longer  simple  but  complex  in  character. 

It  is  so  for  the  reason  that  the  causes  which  have  opera- 
ted to  produce  it  must  be  fully  recognized,  and  the  treat- 
ment to  be  followed  will  be  more  or  less  elaborate  in 
character. 

The  great  majority  of  irregularities  of  the  incisor  teeth 
are  associated  with  decided  malposition  of  the  cuspid  teeth. 

Inasmuch  as  these  latter  teeth  are  the  last  of  the  perma- 
nent set  to  erupt  with  the  exception  of  the  second  and  third 
molars,  and  as  in  some  instances,  they  are  tardy  in  eruption 
and  so  make  their  appearance  after  the  second  molars  are 
in  place  it  will  be  seen  that  if  there  be  any  interference  with 
the  regular  order  or  time  of  eruption  of  the  earlier  appear- 
ing teeth  the  cuspids  will  be  placed  at  a  disadvantage  and 
suffer  somewhat  in  consequence.  As  previously  explained 
the  premature  loss  of  any  of  the  deciduous  teeth  will  be 
almost  certain  to  derange  the  order  of  the  permanent  ones 
by  lessening  the  space  needed  for  their  accommodation. 

Even  if  the  deciduous  molars  and  incisors  are  retained 
for  their  full  time  the  early  loss  of  the  deciduous  cuspids 
will  allow  the  permanent  incisors  to  move  lingually  (or  fail 
to  move  labially)  and  thus  preempt  the  space  which  nor- 
mally belonged  to  the  permanent  cuspids. 

172 


COMPLEX    IRREGULARITIES. 


173 


FIG.  121. 


Fig.  121  shows  this  condition  perfectly  and  furnishes  one 
reason  why  the  most  expressive  teeth  of  the  permanent  set 
are  so  frequent- 
ly found  in 
malposition. 

The  misfort- 
une of  their 
misplacement 
however,  is  not 
confined  to 
themselves,  for 
often  in  their 
efforts  to  wedge 
their  way  into 
place  they  bear 
upon  the  later- 
al incisors, 

J  Lingual  Misplacement  of  Incisors  and  Malposed  Cuspids. 

partly  overlap, 

and  either  rotate  them  in  their  sockets  or  force  them  into 

decided  lingual  malposition,  thus  greatly  complicating  the 

malarrangement. 

This  malposition  of 
the  anterior  teeth  may 
be  associated  with  (a) 
normal  occlusion  of  the 
buccal  teeth,  or  (b)  with 
malocclusion  of  the  same 
teeth. 

a.    NORMAL  BUCCAL    OC- 

CL  USION. While    we 

may  have  normal  buc- 
cal occlusion  (mesio- 
distally)  associated  with 

t      •  -,     -i  i          •.•  /»  Buccal  Benocclusion,  with  Anterior  Malocclusion. 

decided    malposition    of 

certain  of  the  anterior  teeth  as  shown  in  Fig.  122  it  will  nearly 

always  be  noticed  that  the  arch  is  lacking  in  its  normal  width. 


FIG.  122. 


174 


ORTHODONTIA. 


FIG.   123. 


Where  the  upper  arch  is  narrow  and  the  upper  and  lower 
buccal  teeth  are  in  normal  mesio-distal  occlusion  it  will 
generally  be  found  necessary  to  expand  both  arches  in  order 
to  retain  or  secure  proper  occlusion. 

TREATMENT. 

The  upper  arch  may  be  widened  by  either  spring  pressure 
or  the  screw.  The  jackscrew  will  deliver  more  force  and 
accomplish  the  desired  end  in  less  time  than  the  spring,  but 
it  seriously  interferes  with  the  movements  of  the  tongue  in 
speech  and  mastication.  For  these  reasons  also  it  cannot  be 

employed     across 
the  lower  arch. 

Fig.  123  shows 
the  usual  manner 
of  applying  and 
operating  the  jack- 
screw  in  the  upper 
arch. 

By  having  holes 
in  the  bar  connect- 
ing    the     anchor 
bands  on  one  side 
__  and  slots  in  the  bar 

Expansion  by  Screw  (Goddard).  Qn      tne      Opposite 

one  the  screw  can  be  changed  in  its  position  from  time  to 
time  so  as  to  apply  the  major  part  of  the  force  farther  forward 
or  farther  back. 

Expansion  by  means  of  a  spring,  after  the  manner  sug- 
gested by  Dr.  Goddard,  is  illustrated  by  Fig.  124.  It  really 
consists  in  the  employment  of  two  springs ;  a  curved  spring 
of  piano-wire,  within  the  arch  and  a  bow-wire  spring  of  hard 
drawn  German  silver  wire  on  the  outside.  The  ends  "  a  " 
and  "  b  "  are  sprung  into  tubes  attached  to  an  anchor  band 
on  each  side  as  shown. 

The  palatal  spring  with  a  coil  in  it  possesses  no  advantage 
over  the  plain  one  "  c  "  The  latter  is  quite  as  powerful  and 


COMPLEX    IRREGULARITIES. 


175 


can  be  made  to  lie  closer  to  the  roof  of  the  mouth.  For 
widening  the  lower  arch  or  any  portion  of  it  the  author  pre- 
fers the  curved  piano- 
wire  spring  to 
other  device. 


FIG.  124. 


Combination  Appliance  for  Expansion  (Goddard). 


any 
Its 

form  and  adjustment 
are  shown  in  Fig.  125. 
In  this  case  it  was 
desired  to  widen  the 
lower  arch  in  the 
region  of  the  second 
bicuspid  and  first 
molar  teeth  in  order 
to  meet  the  occlusion 
of  the  upper  ones 
which  had  also  been 
moved  buccally. 
Each  of  the  two  molar  bands  had  a  short  tube  soldered 
to  its  lingual  surface  to  receive  one  end  of  the  spring,  while 
the  bicuspid  bands  FlG  125. 

had  short  open 
tubes  fitted  to  them 
for  the  spring  to 
rest  in.  These  bi- 
cuspid open  tubes 
served  to  keep  the 
wire  spring  from 
moving  up  and 
down  in  response 
to  the  motions  of  I 
the  tongue  and 
also  enabled  the 
spring  to  exert  its 

pressure     Upon  Lower  Lateral  Expansion. 

these  teeth  which  needed  buccal  movement  though  in  a  less 
<legree  than  the  molars. 


176 


ORTHODONTIA. 


FIG.  126. 


A  little  enlarging  of  the  curve  of  the  spring  every  few 
days  carried  the  case  along  rapidly.  A  stiff  steel  spring  of 
this  form  is  sometimes  hard  to  insert  in  the  back  part  of  the 
lower  arch,  but  if  a  notch  be  ground  in  each  beak  of  a  lower 
incisor  root  forceps  near  the  point,  the  spring,  after  being 
inserted  in  one  tube  may  be  grasped  by  the  forceps  and 
readily  inserted  in  the  other: 

Either  arch  may  also  be  widened  by  the  Coffin  split-plate 
method  as  described  in  Part  II,  Chapter  III.  After  lateral 
enlargement  of  the  arch  the  anterior  teeth  will  have  to  be 
placed  in  normal  alignment. 

Probably  no  appliance  equals  the  arch  wire  for  effective- 
ness in  operations 
of  this  character. 
Its  thread-cut  ends 
play  in  horizontal 
tubes  attached  to  the 
buccal  surfaces  of 
bands  on  the  anchor 
teeth,  usually  the 
first  molars.  With 
its  nuts  operating 
against  the  anterior 
ends  of  the  anchor 
tubes  it  will  move 
labially  and  carry 
with  it  any  teeth  that  may  have  been  ligated  to  it  for  the 
purpose  as  shown  in  Fig.  126.  With  the  nuts  placed  at 
the  distal  ends  of  the  tubes  their  turning  will  cause  the 
arch  wire  to  move  backward  and  carry  lingually  any 
anterior  teeth  in  contact  with  it. 

Again,  by  its  stiffness  and  elasticity  it  will  often  assist  in 
the  lateral  expansion  of  the  arch  at  the  same  time  that  it  is 
being  employed  for  other  movements. 

A  close  examination  of  Fig.  126  will  show  how  it  may  be 
used  for  distal  movement  of  the  molars,  the  labial  and 


Expansion  Arch  (Canning). 


COMPLEX    IRREGULARITIES.  177 

buccal  movement  of  the  laterals  and  first  bicuspids  and  the 
rotation  of  the  centrals.  The  brass  wire  ligatures  connect- 
ing the  various  teeth  with  the  arch-wire  and  their  manner 
of  attachment  in  order  to  produce  the  different  movements 
are  pretty  clearly  illustrated. 

In  the  foward  movement  of  the  wire  arch  under  the  influ- 
ence of  the  nuts,  it  would,  if  smooth,  slip  through  most  of 
the  wire  ligatures  FIG  12?' 

attached  to  it  and 
thus  do  very  little 
good. 

To  prevent  this  it 
is  customary  to  soft 
solder  small  sections 
of  G.  S.  tubing  or 
wire  spurs  or  hooks 

at  mail}7  points  along  Indented  Expansion  Arch  (Canning). 

the  outer  surface  of  the  arch  wire  so  that  the  ligatures 
will  be  carried  along  with  it. 

Another  method  of  preventing  the  slipping  forward  of  the 
wire  arch  is  that  devised  by  Mr.  Canning  and  known  as 
his  Indented  Expansion  Arch.  Fig.  127  will  give  some  idea 
of  it.  It  is  a  hard  drawn  German  silver  wire  arch  of  the 
usual  pattern  except  that  it  is  deeply  indented  along  the 
surface  that  comes  in  contact  with  the  lip.  These  indenta- 
tions are  of  such  character,  that  while  deep  enough  to 
enable  the  wire  ligature  to  take  a  firm  hold,  they  do  not 
have  sharp  edges  and  cannot  irritate  the  mucous  mem- 
brane. 

b.  BUCCAL  MALOCCLUSION — Where  anterior  malposition  is 
associated  with  buccal  malocclusion,  the  latter  may  be  either 
unilateral  or  bilateral. 

When  unilateral,  it  is  undoubtedly  due  to  premature 
extraction  of  some  deciduous  tooth,  usually  the  cuspid,  on 
one  side  only,  thus  diminishing  the  size  of  that  particular 
half  of  the  arch. 


178  ORTHODONTIA. 

Two  buccal  views  of  this  condition,  with  upper  and 
lower  teeth  in  occlusion,  are  shown  in  Fig.  128.  On  one  side 
the  buccal  occlusion  is  normal,  while  on  the  other  the  lower 
teeth  are  in  postocclusion  the  width  of  a  bicuspid  tooth. 

FIG.  128. 


Unilateral  Malocclusion  (.Knapp). 

Bilateral  malocclusion  in  connection  with  irregularity  of 
the  anterior  teeth  is  simply  one  degree  worse  than  unilateral 
because  it  favors  still  greater  disturbance  of  the  normal 
arch  line  in  all  directions  with  a  crowding  of  the  teeth  at 
various  points  as  shown  in  Fig.  129. 

FIG.  129. 


Crowded  Lower  Arch. 

The  side  teeth,  either  bicuspids  or  molars,  when  in  mal- 
occlusion are  not  often  found  outside  of  the  arch  line  but  are 
usually  one  step  anterior  to  their  normal  positions  owing  to 
the  space  afforded  by  the  crowded  anterior  teeth. 


CLASS  II. 


FIG.  130. 


UPPER   PROTRUSION. 

This  deformity,  in  greater  or  less  degree,  is  very  fre- 
quently met  with  and  is  one  that  so  materially  changes  the 
normal  facial  expression  as  to  call  for  prompt  remedy. 

It  is  so  characteristic  of  certain  forms  of  imbecility  as  to 
suggest  that  condition  and  thus  do  great  injustice  to  the 
individual.  The  causes  responsible  for  it  are  various,  but  as 
it  manifests  itself  early  in  life  and  is  generally  associated 
with  mouth-breathing,  the  most  common  cause  probably  is 
the  presence  of  adenoids  in  the  naso-pharynx. 

As  these  do  not  disappear  of  their  own  accord  before 
puberty  and  as  by  that  time  the  malposition  of  the  teeth 
will  have  be- 
come confirmed 
the  necessity  for 
the  removal  of 
the  growths  and 
the  correction  of 
the  deformity  as 
soon  as  discov- 
ered is  impera- 
tive. 

Even  though 
certain  of  the 
deciduous  teeth 
still  remain 
the  operation 
should  not bede- 
layed,  because 

with    lapse     of  Typical  Cftse  of  Upper  Protrusion- 

time  the  difficulties  of  correction  and  retention  are  increased. 


179 


180  ORTHODONTIA. 

Associated  with  the  anterior  protrusion  we  usually  have 
a  narrowing  of  one  or  both  arches;  indeed,  without  this 
narrowing  of  the  upper  arch  at  least,  and  with  all  of  the 
buccal  teeth  present  and  in  normal  anterior-posterior  occlu- 
sion, it  is  doubtful  whether  the  abnormity  could  occur. 

Owing  to  the  undue  prominence  of  the  upper  anterior 
teeth  the  lower  incisors  do  not  come  into  occlusion  with 
them,  and  in  consequence  are  disposed  to  become  somewhat 
extruded  until  their  incisal  edges  barely  touch  the  bases  of 
the  upper  crowns  or  in  some  extreme  cases  come  in  con- 
tact with  the  gum  tissue  posterior  to  them. 

Fig.  130  is  a  typical  example  of  this  condition.  While  the 
deformity  under  consideration  pertains  strictly  to  the  upper 
teeth  and  arch  it  is  necessarily  related  to  the  lower  ones,  for 
the  latter  may  be  in  normal  position  and  arch  relation  or 
they  may  be  retruded. 

Lower  Teeth  Normal. — Fig.  131  illustrates  this  type,  in 
which  the  lower  teeth  not  only  preserve  their  normal  arch 
FlG  131  alignment  but  are  in  nor- 

mal or  benocclusion  with 
the  upper  ones  so  far  as  the 
buccal  teeth  are  concerned. 
As  in  these  cases  the 
irregularity  is  entirely 
confined  to  the  four  upper 
incisors  the  condition  can 
only  be  attributed  to  some 
unusual  peculiarity  of 
alveolar  development. 

Upper  Protrusion.    Lower  Normal  "iiru  j.u       i 

Where   the  lower  arch 

s  normal  in  size  and  outline  and  malocclusion  exists  as 
m  Fig.  132,  it  would  seem  that  there  has  been,  for  some 
unexplamable  reason,  an  over  development  of  the  entire 
upper  arch. 

The  space  between  the  upper  anterior  teeth  in  this  and 
similar  cases  could  hardly  be  explained  in  any  other  way, 


UPPER    PROTRUSION.  181 

inasmuch  as  the  incisors  in  each  jaw  do  not  come  into  occlu- 
sion, and,  therefore,  the  lower  could  not  be  held  accountable 
for  the  protrusion  of  the  FlG  132 

upper  ones. 

Lower  Teeth  Retruded. 
— Retrusion  of  the 
lower  teeth  in  connec- 
tion with  protrusion  of 
the  upper  is  more  fre- 
quently met  with  than 
the  condition  just  de- 
scribed. Fortunately, 
however,  with  present 
appliances  and  especi- 
ally with  the  aid  of 

Upper  Protrusion  with  Malocclusion  (Weeks). 

intermaxillary    elastics 

which  exert  equal  force  on  the  teeth  of  each  jaw  this  double 
irregularity,  so  to  speak,  is  more  amendable  to  successful 
treatment  than  where  the  lower  teeth  are  not  to  be  moved 
at  all. 

Fig.  133  is  a  good  illustration  of  this  bimaxillary  de- 
formity where  buccal  malocclusion  exists  only  on  one  side 
of  the  mouth.  There  is  great  protrusion  of  the  upper 
anterior  teeth  and  retrusion  of  the  lower  anterior  ones 
acccompanied  by  extrusion,  thus  creating  an  excessive 
overbite  with  a  falling  in  of  the  lower  lip.  No  teeth  are 
missing,  and  while  normal  occlusion  exists  on  one  side 
of  the  arch  there  is  postocclusion  of  the  lower  teeth  on  the 
opposite  side  equal  to  the  width  of  a  bicuspid  tooth. 

Fig  134  represents  lower  retrusion  of  a  somewhat  different 
character. 

Here  there  is  unusual  protrusion  of  all  of  the  upper  teeth, 
but  the  retrusion  in  the  lower  is  largely  confined  to  the 
incisors.  These  lower  incisors  are  not  extruded,  and  in 
consequence  there  is  a  large  space  in  the  front  part  of  the 
mouth  interfering  greatly  with  both  speech  and  mastication. 


182 


ORTHODONTIA. 


FIG.  133. 


Treatment. — In  all  cases  of  upper  protrusion  lingual  or 
backward  movement  of  the  protruding  teeth  is  the  proper 
remedy,  but  it  must  be  seen  to  in  advance  that  opportunity 

exists   for  such 
movement. 

If  the  lower 
teeth  are  in  nor- 
mal position 
and  the  lower 
incisors  are  not 
extruded  force 
can  be  brought 
to  bear  upon 
the  teeth  of  the 
upper  arch  so  as 
to  compel  their 
lingual  and  dis- 
tal movement 
provided  there 
is  space  for  the 
moving  teeth  to 
occupy.  Very 
often  such  space 
exists  between 
the  different 
anterior  teeth, 
and,  if  so,  the 
proposed  move- 
ment should  not 
prove  to  be  a 
difficult  one. 

Where,  how- 
ever, the  lower 
incisors  are  much  extruded  it  will  be  found  that  the  burden 
of  mastication  having  fallen  upon  the  bicuspids  and  molars 
these  have  been  to  some  extent  intruded.  In  these  cases, 


Upper  Protrusion  with  Lower  Retrusion 
and  Unilateral  Postocclusion. 


TREATMENT. 


183 


FIG.  134. 


therefore,  there  necessarily  will  be  three  different  changes 
to  be  brought  about. 

The  extruded  lower  incisors  must  be  intruded,  the 
intruded  bicuspids 
and  molars  must  be 
extruded  and  the 
upper  teeth  must  be 
retruded. 

The  first  two 
operations  are  pre- 
liminary to  the  third, 
for  unless  the  lower 
incisors  be  intruded 
they  will  interfere 
with  or  prevent  the 
lingual  movement  of 

the     Upper      incisors,  Upper  Protrusion.    Lower  Retrusion. 

and  unless  the  lower  buccal  teeth  be  extruded  they  will  not 
come  into  occlusion  with  their  corresponding  ones  above 
after  the  third  movement  has  been  accomplished. 

There  are  three  different  methods  of  bringing  about  the 
intrusion  of  the  lower  incisors  and  the  extrusion  of  the  lower 
bicuspids  and  molars  at  the 
same  time. 

1.  The  old  method  of  con- 
structing a  vulcanite  bite-plate 
to  fit  the  roof  of  the  mouth  and 
having  it  thickened  in  front  to 
afford  a  flat  surface  for  the 
lower  incisors  to  bite  against,  as 
is  shown  in  Fig.  135.  It  may 
contain  a  vacuum  chamber  or 
not,  as  preferred,  but  it  ought  vulcanite  Bite  Plate. 

to  fit  the  roof  accurately,  and  therefore  should  be  made  from 
a  plaster  impression. 

As   the  bite   is  temporarily  opened   the   bicuspids   and 
molars  of  both  jaws  will  gradually  become  extruded  while 


FIG.  135. 


184 


ORTHODONTIA. 


FIG.  136 


the  lower  incisors  by  constant  impact  against  the  plate  will 
become  intruded. 

The  plate  will  not  be  uncomfortable  and  the  patient  will 
soon  become  accustomed  to  its  presence. 

If  it  be  worn  for  a  year,  as  it  should  be,  at  the  end  of  that 
time  the  desired  extrusion  and  intrusion  will  both  have 
taken  place.  No  attempt  to  correct  the  real  deformity 
(upper  protrusion)  should  be  made  until  this  preliminary 
change  has  been  brought  about. 

2.  The  plan  of  Dr.  Case  in  which  the  teeth  to  be  extruded 
as  well  as  those  to  be  intruded  are  surrounded  by  metal 
bands  with  wire  hooks  soldered  to  their  labial  or  buccal  sur- 
faces. Those  to  be  extruded  have  the  hooks  bent  toward  the 
gum  while  those  to  be  intruded  have  their  hooks  curved  in 
the  opposite  direction,  all  as  shown  in  Fig.  136. 

To  one  of  the  molars  on  each  side  is  fitted  a  band  with  a 
horizontal  open 
tube  attached. 
With  the  bands 
all  in  place,  a 
thin  but  stiff 
German  silver 
wire  is  inserted 
in  the  molar 
tube  on  one  side, 
passed  under 
the  hooks  on 

the       bicuspids,  Extrusion  and  Intrusion  (Case). 

over  those  on  the  incisors,  again  under  those  of  the  bicus- 
pids on  the  opposite  side  and  secured  in  the  tube  on  the 
molar  on  that  side. 

The  action  of  the  wire,  curved  in  the  manner  indicated 
will  be  to  extrude  the  bicuspids  and  intrude  the  incisors- 
As  the  extruding  of  a  tooth  is  much  more  readily  accom- 
plished than  the  intruding,  the  bent  wire  may  not  act 
equally  in  depressing  some  teeth  and  elevating  others,  but 


TREATMENT. 


185 


this  can  usually  be  regulated  by  the  one  in  charge  of  the 


case. 


FIG.  137. 


3.  The  third  method  for  extrusion  and  intrusion  is  that  of 
Dr.  Knapp  and  consists  of  metal  bands  made  to  fit  the  upper 
incisors  and  having  curved  metal 
lugs  attached  to  their  lingual  por- 
tions as  shown  in  Fig.  137.  These 
lugs  are  so  fashioned  and  placed  that 
the  lower  incisors  must  glide  into 
them  when  the  jaws  are  closed,  and 
as  they  prevent  full  occlusion  all 
mastication  must  be  performed  by 
the  four  lower  incisors  which  permits 
gradual  extrusion  of  the  posterior 
teeth,  just  as  in  plan  1. 

When  a  greater  opening  of  the 
bite  is  desired  the  lugs  may  be 
thickened  so  as  to  extend  nearer  to 
the  incisal  edges  of  the  teeth,  as 
in  Fig.  138. 

With   the   bite  opened    so   as    to 
avoid  interference  on  the  part  of  the  lower  teeth  we  next 
proceed  to  reduce  the  upper  protrusion. 

There  are  two  satisfactory    plans   for  retruding  the   six 
anterior   teeth.      One   is   to   move   them        FlG 138 
backward  by  pairs  (one  on  each  side  at 
the   same  time)  and   the  other   to   move 
them  all  at  one  time  or  in  phalanx. 

The  first  plan  is  slower  but  has  the 
advantage  of  not  requiring  the  employ- 
ment of  conspicuous  appliances.  The 
second  is  more  rapid,  but  for  the  obtain- 
ing of  best  results,  its  use  must  be  limited 
to  patients  still  too  young  to  be  sensitive 
about  personal  appearance. 

Where  we  can  obtain  good  firm  anchorage  in  the  back 
part  of  the  arch,  as  by  the  combination  of  two  molars  and  a 


Opening  Bite  (Knapp). 


186  ORTHODONTIA. 

second  bicuspid,  the  moving  of  the  anterior  teeth  by  pairs 
is  the  better  plan,  as  described  on  page  152. 

If  a  first  bicuspid  on  each  side  should  be  missing,  or  if 
there  be  spaces  between  the  anterior  teeth  there  ought  to  be 
no  difficulty  in  retracting  them  by  this  method. 

Two  molar  bands,  and  sometimes  a  third  (on  the  second 
bicuspid)  are  fitted  and  soldered  together.  A  tube  long 
enough  to  extend  along  the  buccal  surfaces  of  the  molars  is 
then  united  to  the  molar  bands.  Another  band  with  a 
short  vertical  tube  is  adapted  to  the  cuspid  crown.  With 
all  of  these  bands  loosely  in  position  a  short  rod  of  G.  S. 
wire  is  bent  at  a  right  angle  at  one  end  and  threaded  for  at 
least  half  of  an  inch  at  the  other.  A  nut  is  also  provided 
for  it.  This  traction  screw  should  be  curved  at  its  free 
portion  (outside  of  the  tube)  to  conform  to  the  curve  of  the 
arch.  When  all  parts  have  been  properly  fitted  and 
adjusted  they  are  removed  preparatory  to  being  placed  per- 
manently in  position.  The  molar  bands  should  now  be 
dried  and  roughened  on  their  inner  surfaces  with  an  excava- 
tor, the  screw  inserted  in  the  tube  and  its  nut  started  into 
place.  After  applying  a  napkin  around  the  teeth  and  gums, 
the  molar  teeth  should  be  wiped  with  a  pellet  of  cotton 
dipped  in  alcohol  and  dried  with  a  warm  air  syringe  in  the 
hands  of  an  assistant. 

The  bands  (with  the  screw  loosely  in  place)  are  next  lined 
with  zinc-phosphate  and  pressed  into  position.  After  allow- 
ing five  minutes  for  the  hardening  of  the  cement  the  cuspid 
band  is  treated  and  cemented  into  place  in  the  same 
manner. 

After  applying  the  cement  to  this  latter  band  its  tube 
should  be  slipped  over  the  bent  end  of  the  traction  screw 
and  the  band  swung  into  place  upon  the  tooth.  If  all  of 
the  bands  were  set  first  and  independently  of  the  screw,  it 
would  be  very  difficult  to  get  the  latter  into  position. 

The  author  has  never  felt  the  necessity,  as  advocated  by 
some  orthodontists,  of  applying  the  rubber  dam  for  the 


TREATMENT.  187 

cementing  of  bands.  The  parts  can  certainly  be  kept  dry 
for  five  minutes  or  longer  without  it  and  much  discomfort 
spared. 

With  an  appliance  such  as  the  one  just  described  fitted  to 
each  side  of  the  arch  the  cuspids  can  be  drawn  backward 
with  safety  if  the  operation  is  not  hurried.  Moreover,  the 
patient,  being  supplied  with  a  wrench  and  instructed  as  to 
its  use,  can  turn  the  nut  and  really  perform  the  work  him- 
self under  the  occasional  supervision  of  the  operator.  After 
the  cuspids  have  been  sufficiently  retruded  they  should  be 
wired  to  the  molar  fixture  for  temporary  retention  while  the 
laterals  are  being  moved  back  in  similar  manner  with  a 
longer  traction  screw. 

The  laterals  are  then  wired  to  the  cuspids.  The  centrals 
may  now  be  retracted  by  means  of  a  rubber  band  caught 
over  the  distal  end  of  one  molar  tube,  passed  along  the 
labial  and  buccal  surfaces  of  all  of  the  teeth  and  slipped 
over  the  molar  tube  on  the  opposite  side. 

To  retain  this  rubber  in  position  in  front,  one  of  the 
incisors  should  be  fitted  with  a  metal  band  having  a  V- 
shaped  wire  or  lug  soldered  to  its  labial  surface.  The  rub- 
ber will  rest  in  this  lug  and  be  quite  secure. 

When  a  satisfactory  rearrangement  of  the  anterior  teeth 
has  thus  been  effected  they  may  be  held  by  means  of  a 
retainer  similar  to  the  one  shown  in  Fig.  72. 

With  the  six  teeth  thus  held  as  a  unit  they  will  not  be  likely 
to  again  move  forward,  but  it  must  be  borne  in  mind  that 
the  results  of  corrected  upper  protrusion  are  harder  to  retain 
than  any  other  form  of  corrected  mal-position  owing  to  the 
direction  of  force  applied  to  them  in  mastication  afterward. 

It  is  therefore  important  that  any  retaining  device 
employed  in  these  cases  should  be  worn  for  at  least  a  year, 
and  in  some  cases  for  two  years. 

For  retruding  the  upper  anterior  teeth  in  phalanx  much 
more  force  will  be  required  than  when  they  are  to  be 
moved  in  pairs.  This  force  can  only  be  obtained  through 


188 


ORTHODONTIA. 


occipital  anchorage.  Dr.  Kingsley,  we  believe,  was  the  first 
practitioner  to  suggest  and  utilize  the  back  or  dome  of  the 
head  as  an  anchorage  for  appliances  intended  to  produce 
movements  of  the  teeth.  Illustrations  of  an  appliance  for 
this  purpose  are  shown  in  his  book,  pp.  133  and  134.  Modi- 
fications were  introduced  by  Dr.  Farrar  and  Prof.  Goddard 
but  the  type  of  the  one  most  in  favor  to-day  is  the  result  of 
the  ingenuity  of  Dr.  Angle.  His  appliance  is  shown  in 

Fig.  139. 

FIG.  139. 


Angle's  Retraction  Appliances. 


It  consists  of  anchor  bands  (D)  for  the  molar  teeth,  with 
long  tubes  soldered  to  their  buccal  surfaces  to  receive  the 
wire  bow  spring  (C)  which  rests  in  front  in  notched  projec- 
tions upon  bands  (A)  cemented  to  the  central  incisors.  At 
the  center  of  the  bow-spring  is  soldered  a  short  tube,  having 
upon  its  labial  surface  a  rounded  projection  to  receive  the 
standard  (cupped  at  its  free  end)  of  the  long  traction  bar 
(E).  In  use,  the  clamp-bauds  (D)  are  attached  to  the  anchor 
teeth  and  the  plain  bands  (A)  cemented  to  the  central  incis- 
ors. The  bow-spring  (C)  is  now  placed  in  position. 


TREATMENT. 


189 


Occipital  resistance  is  obtained  by  means  of  a  netted  cap 
fastened  to  a  circle  of  wire  fitted  to  the  head,  to  which  are 
attached  rubber  bands.  When  the  cupped  standard  of  the 
traction  bar  has  been  placed  over  the  central  spur  of  the 
bow-spring,  the  rubber  bands  of  the  cap  are  drawn  forward 
and  looped  over  the  curved  ends  of  the  traction  bar,  as 
shown  in  Fig.  142.  This  cap,  traction  bar  and  rubber  bands 
are  worn  only  at  night  on  account  of  their  conspicuous- 
ness. 

During  the  day,  rubber  rings  (B)  are  caught  over  the 
tubes  on  the  molar  bands  and  secured  by  ligature  to  projec- 
tions on  the  bow-spring  in  the  region  of  the  cuspid  teeth. 

The  author's  method  of  employing  occipital  resistance  for 
retrusion  differs  in  some  of  its  details  from  the  Angle  method. 

FIG.  140. 


Author's  Combination  for  Retrusion. 


A  cap  of  silver  plate,  30,  is  swaged  to  fit  and  cover  the  entire 
crowns  of  the  central  incisors  without  occupying  any  inter- 
dental space.  On  its  labial  surface  near  the  distal  edges  are 
soldered  two  headed  pins  taken  from  vulcanite  teeth  and 


190  ORTHODONTIA. 

midway  between  these  a  short  pin  or  post  of  platinous  gold 
wire  is  also  attached  to  engage  with  the  Angle  Traction  Bar. 
The  molars  are  fitted  with  metal  bands  to  which  hooks  are 
attached  on  their  buccal  surfaces,  all  as  shown  in  Fig.  140. 
The  skull-cap  is  made  in  skeleton  form  of  inch-wide  strips 
of  sheep-skin  leather  sewed  together,  using  the  undyed  skin 
for  patients  with  light-colored  hair,  and  dark  leather  for 
brunettes.  A  pattern  of  paper  strips  is  first  made  and  fitted 
to  the  head,  and  from  this  the  one  of  leather  is  formed. 

FIG.  141.  Fig.  141  shows  one  side  of  the  cap 

with  the  manner  of  uniting  the  strips 
where  the}'  pass  around  the  ear.  In 
use,  the  silver  saddle  is  placed  in 
A  position  upon  the  centrals  and  the 
headed  pins  connected  with  the  hooks 
on  the  molar  bands  by  means  of  thin 
rings  cut  from  rubber  tubing. 

The  skull-cap  is  next  placed  upon 
the  head ;  the  cupped  post  of  the  trac- 
Author's  skuii-cap.  tion  bar  adjusted  to  the  central  pin  on 
the  saddle,  and  the  ends  of  this  bar  connected  with  the 
hooks  on  the  skull-cap  by  means  of  elastics.  The  elastics 
used  are  the  ordinary  flat  rubber  bands,  about  half  an  inch 
wide,  cut  into  sections  of  suitable  length  and  perforated  near 
their  extremities.  The  entire  appliance  is  to  be  worn  from 
the  close  of  school  each  day  until  the  opening  of  school  on 
the  following  one,  but  during  school-hours  the  skull-cap  and 
traction  bar  are  dispensed  with. 

Thus,  for  sixteen  hours  out  of  the  twenty-four  constant 
force  is  being  exerted  upon  the  teeth,  while  during  the 
remaining  eight  hours  the  delicate  elastic  bands  retain  the 
advancement  made. 

In  several  cases  the  author  has  been  able  to  persuade  the 
young  patients  to  wear  the  appliance,  including  traction 
bar  and  skull-cap,  both  day  and  night  during  their  two  or 
three  months'  summer  vacation.  By  this  means  very  rapid 
progress  was  made. 


TREATMENT. 


191 


The  direction  of  the  applied  force,  of  course,  must  be  con- 
sidered in  the  arrangement  of  the  appliances.  If  it  be 
simple  retrusion  the  force  should  be  applied  on  a  line  as 
nearly  parallel  as  possible  with  the  line  of  occlusion,  and  to 
effect  this  elastics  of  equal  strength  should  be  attached  to 
the  tabs  A.  A.  of  the  skull-cap  and  extend  to  the  traction 
bar 

Where  both  intrusion  and  retraction  are  desired  the  force 
should  be  exerted  in  a  line  with  the  dome  of  the  head,  and 
where  intrusion  is  the  main  movement  required  the  pressure 
should  be  as  nearly  upward  as  possible. 

Force  can  be.  regulated  in  any  way  by  varying  the  strength 
of  the  elastics,  having  one 
weak  and  the  other  strong, 
according  to  requirement. 

Fig.  142  shows  the  au- 
thor's arrangement  of 
skull-cap,  retrusion  bar 
and  elastics  in  position  in 
a  case  where  intrusion  of 
two  of  the  upper  incisors 


FIG.  142. 


Occipito-Maxillary  Appliances  in  Position. 


was  being  accomplished. 
As  the  force  applied  was 
in  a  vertical  direction  as 
nearly  as  possible,  only 
one  elastic  was  used  on 
each  side, the  cap  retaining 
its  position  perfectly  not- 
withstanding this  seeming 
lack  of  balance.  Realizing  and  appreciating  the  great 
force  that  can  be  applied  by  means  of  the  occipito-maxillary 
device  the  author  feels  constrained  to  utter  a  word  of  caution 
as  to  its  overuse.  A  force  so  powerful  needs  careful  over- 
sight in  order  to  avoid  accidental  results.  As  an  illustra- 
tion of  this  fact  notice  Fig.  143.  It  represents  a  model  sent 
to  the  author  for  advice  in  regard  to  remedying  the  unin- 


192 


ORTHOPONTIA. 


143. 


tentional  extrusion  and  buccal  displacement  of  the  upper 
first  molars,  a  result  of  the  too  vigorous  application  of  the 
headgear  and  bar  in  a  case  of  upper  protrusion. 

One  of  the  most 
recent  and  at  the 
same  time  most  ef- 
ficient methods  of 
producing  retru- 
sion  of  the  upper 
and  protrusion  of 
the  lower  teeth  at 
the  same  time  is 
by  the  use  of 
the  intermaxillary 
elastics  as  first 
suggested  by  Case. 
A  diagrammatic 
representation  of 
their  application 
and  operation  is  shown  in  Fig.  144.  They  are  intended  to  be 
used  in  connection  with  bow  wires  which  have  been  adjusted 

to  both  upper  and  lower 
arches  expressly  for  this  pur- 
pose or  for  some  other  move- 
ment which  is  to  take  place 
concurrently.  In  the  lower 
arch  (in  this  case)  the  elastic 
ring  is  caught  over  the  pro- 
truding end  of  the  bow- wire 
or  the  tube  through  which  it 
passes  and  stretched  to  en- 
gage with  a  hook  attached 
to  the  upper  bow  wire  somewhere  in  the  region  of  the 
cuspid  teeth. 

To  produce  the  best  results  the  elastic  should  be  in  as 
nearly  a  horizontal  position  as  possible  and  to  accomplish 


Ill-Results  of  Overapplication. 


144. 


Intermaxillary  Elastics  (Case). 


TREATMENT.  193 

this  it  should  be  attached  as  far  forward  as  possible  in  the 
one  arch  and  as  far  back  as  may  be  in  the  other.  When 
the  jaws  open  the  rubber  tends  toward  a  vertical  position 
and  traction  then  operates  to  lift  the  teeth  from  their 
sockets.  This  tendency  would  be  increased  with  the  attach- 
ments for  the  rubber  closer  together.  This  extruding  force 
of  the  elastics  constitutes  the  main  objection  to  their  use 
and  therefore  they  should  never  be  attached  to  an  indi- 
vidual tooth  at  either  end  for  the  tooth  would  almost  cer- 
tainly be  extruded  and  thus  lead  to  complications. 

If  the  bow-wire  is  not  employed  joined  metal  bands 
should  be  attached  to  the  anchor  teeth  to  offer  sufficient 
resistance  to  the  extrusive  force  of  the  elastics  and  to  keep 
the  teeth  in  alignment. 


CLASS  III 


Fig.  145. 


LOWER  PROTRUSION. 

Though  much  less  common  than  upper  protrusion,  this 
deformity  is  of  rather  frequent  occurrence.  Both  forms 
produce  such  a  derangement  of  facial  profile  as  to  attract 
public  attention  and  cause  profound  mortification.  Both 
also  have  their  beginnings  in  very  early  life  and  usually 
arise  from  what  at  first  is  but  a  slight  variation  from  the 
normal  occlusion. 

If  the  upper  centrals  erupt  slightly  lingually,  as  they 
often  do,  even  though  just  sufficiently  to  be  caught  inside 
of  the  incisal  edges  of  the  lower  ones  a  beginning  is  made 
and  the  constant  closing  of  the  teeth  in  this  abnormal  man- 
ner will  continue,  by 
degrees,  to  force  the 
lower  incisors  forward 
and  retain  the  upper 
ones  in  their  lingual 
position. 

If  the  occlusion  of  the 
buccal  teeth  should  not 
prevent,  and  it  usually 
does  not,  there  is  no 
telling  to  what  extent 
the  irregularity  may 
develop. 

A  good  illustration  of 
the  condition  after  the 

eruption  of  the  four  lower  incisors  and  before  the  full  erup- 
tion of  the  upper  laterals  is  furnished  by  Fig.  145. 

When  detected  quite  early  and  brought  to  the  attention 
of  the  orthodontist  a  simple  moving  of  the  upper  incisors 

(194) 


First  Stage  of  Lower  Protrusion  (Knapp). 


LOWER    PROTRUSION.  195 

labially  so  as  to  overlap  the  lower  ones  will  not  only  check 
the  irregularity  but  correct  it  by  forcing  the  lower  teeth 
back  into  normal  position  and  holding  them  there' 

If  neglected  until  all  or  nearly  all  of  the  permanent  teeth 
<ire  erupted  and  in  malocclusion  the  difficulty  of  correction 
will  be  enormously  increased.  With  the  lower  teeth  in 
antocclusion  the  upper  ones  may  be  in  normal  position  or 
they  may  be  retruded.  Even  if  in  normal  position  when  the 
lower  protrusion  first  manifests  itself,  the  upper  incisors  by 
virtue  of  the  inward  force  exerted  upon  them  will  soon 
assume  a  lingual  position. 

With  the  upper  incisors  in  normal  position  the  difficulty 
of  correcting  the  lower  protrusion  will  not  be  so  great.     It 
may  be  accomplished  by  some  of 
the  several  methods  described  in 
Part  3,  Chapter  1,  or  if  preferred, 
the  lower  teeth  may  be  retruded 
by  employing  a  plate  embodying 
the  principle  of  the  inclined  plane 
on  a  somewhat  extended  scale. 

Fig.  146  represents  a  form  of 
plate  which  the  author  has  often 
used  successfully  for  producing 
lower  retrusion  when  the  patient 
was  but  nine  or  ten  years  of  age.  inclined  Plane  Plate. 

It   is   constructed   of  vulcanite 

and  has  inserted  in  its  anterior  portion  pieces  of  platinous  or 
spring-gold  plate  arranged  to  rest  ngainst  the  lingual  sur- 
faces of  the  incisors  and  extend  below  their  incisal  edges. 

To  hold  this  plate  in  place  and  resist  the  leverage  pro- 
duced by  biting  on  the  gold  projections  a  molar  on  each 
side  should  be  fitted  with  a  Magill  band,  to  the  lingual  side 
of  which  is  soldered  an  oval  lug  or  projection.  When  the 
plate  is  inserted  it  is  sprung  up  past  these  lugs,  and  thus 
securely  held  in  position.  The  patient  by  a  slight,  dexter- 
ous movement  can  remove  the  plate  for  cleaning  and  then 
reinsert  it. 


196 


ORTHODONTIA. 


Fig.  147. 


When  so  simple  an  appliance  proves  inadequate  to 
retrude  the  lower  teeth  sufficiently  to  correct  the  deformity, 
the  upper  teeth  being  in  normal  facial  relation,  we  may 
bring  greater  force  to  bear  upon  them  by  adopting  the  plan 
of  Prof.  Case.  Under  the  conditions  just  mentioned  it  is 
his  custom  to  use  occipital  resistance  with  the  bow-wire 
bearing  upon  the  lower  incisors.  The  lower  molars  and 
two  incisors  are  banded  and  an  arch-wire  adapted  to  them. 
To  the  center  of  this  wire,  right  on  the  median  line,  a  spur 
is  soldered  to  receive  the  depressed  post  of  the  retrusion 
bow.  Elastics  connect  the  ends  of  this  bow  with  the  tabs 
of  the  headgear,  as  in  upper  protrusion,  but  with  the  dif- 
ference that  the  tab 
passing  below  the  ear 
is  the  one  to  which 
virtually  all  of  the 
force  is  applied. 

This  appliance  fur- 
nishes the  greatest 
amount  of  force  that 
we  are  capable  of  ex- 
erting upon  the  lower 
teeth  and  should  be 
able  to  retrude  them 
where  other  appli- 
ances fail. 

When  the  upper 
incisors  are  retruded 
we  will  usually  find  that  the  condition  has  been  caused,  at 
least  in  part,  by  the  unfortunate  extraction  of  one  or  more 
of  the  upper  buccal  teeth. 

Our  only  course  to  pursue  in  such  cases  is  to  enlarge  the 
upper  arch  to  its  normal  size  by  means  of  the  expansion 
arch  and  replace  the  missing  teeth  by  artificial  substitution. 
After  that  the  lower  ones  may  be  retruded  and  normal 
occlusion  and  facial  harmony  reestablished. 

Fig.  147  represents  the  class  just  described  in  which  the 


Retrusion  of  Upper  Anterior  Teeth. 


MANDIBULAR    PROTRUSION.  197 

lack  of  harmonious  proportion  between  the  upper  and  lower 
arches  was  most  probably  due  to  the  loss  of  an  upper  bicus- 
pid years  previously. 

MANDIBULAR  PROTRUSION. 

This  condition,  when  pronounced,  creates  one  of  the 
greatest  dento-facial  deformities  of  which  we  have  knowl- 
edge. Once  fully  established  it  is  most  difficult  to  correct. 
Indeed,  we  can  scarcely  hope  for  anything  more  than 
moderate  improvement  as  a  result  of  any  corrective  meas- 
ures that  we  may  apply  and  the  result  will  always  be.in 
inverse  ratio  to  the  extent  Fi  14g 

of  the  deformity. 

Fig.  148  represents  a 
mild  type  of  this  irregu- 
larity in  which  the  teeth  of 
both  jaws  are  in  normal 
vertical  position  but  where 
the  lower  jaw  and  teeth  are 
advanced  the  full  width  of 
a  bicuspid  tooth. 

In  a  case  like  this  if  all 
of  the  upper  teeth  can  be 
protruded  one  half  of  the 

j    j  •    ,  •,!  Mandibular  Protrusion  (Weeks). 

required  distance  without 

producing  too  great  prominence  and  the  lower  ones 
retruded  the  other  half,  normal  occlusion  may  be  restored. 
For  retrusion  of  the  lower  jaw  reliance  is  very  often 
placed  upon  the  use  of  the  head-gear  and  a  chin  appliance 
made  to  fit  approximately  the  chin  and  extend  along  the 
cheeks  far  enough  to  be  connected  with  the  head-piece  by 
rubber  bands.  With  the  dome  of  the  head  used  as  resist- 
ance and  heavy  elastics  furnishing  the  power,  great  force 
can  be  applied  to  the  chin  and  thus  transmitted  to  the 
temporo-mandibular  articulation  but  it  is  doubtful  whether 
much  change  can  be  effected  by  this  means.  Some  slight 


198  ORTHODONTIA. 

retrusion  of  the  mandible  can  be  effected  early  in  life,  prob- 
ably through  the  compression  of  the  capsular  ligament,  but 
experience  seems  to  prove  that  there  is  little  if  any  resorp- 
tion  of  the  posterior  wall  of  the  glenoid  fossa.  Usually  the 
great  force  applied  will  cause  such  severe  headache  and  dis- 
comfort as  to  necessitate  the  discontinuance  of  the  effort. 

In  nearly  all  cases  of  this  character  the  author  has  found 
that  after  continued  effort  to  ret  rude  the  lower  jaw  it  became 
necessary  eventually  to  extract  the  two  first  bicuspids  and 
then  retrude  the  anterior  teeth.  The  prominence  of  the 
chin  is  not  reduced  by  this  procedure,  but  by  inclining  the 
lower  anterior  teeth  lingually  and  the  upper  ones  labially  a 
compromise  can  be  effected  by  which  the  occlusion  and 
facial  outline  will  be  more  harmonious  than  they  were 
originally. 


CLASS  IV. 


FIG.  149. 


UPPER  RETRUSION  WITH  LOWER  NORMAL. 

Although  cases  of  this  class  are  sometimes  met  with  they 
are  exceedingly  rare.  We  can  conceive  of  no  reason  why 
the  upper  teeth  should  be  in  a  real  or  apparent  retruded 
condition  except  through  lack  of  normal  development  or 
by  reason  of  the  loss  of  one  or  more  teeth. 

Usually  upper  retrusion  is  accompanied  by  lower  pro- 
trusion, the  latter  condition  being  largely  responsible  for 
the  former  one,  but  with  the  lower  teeth  normally  placed  it 
would  seem  to  be  impossible  for  them  to  have  in  any  way 
caused  the  upper  retru- 
sion, for  if  they  had  they 
would  themselves  have 
become  protruded  in  the 
very  act. 

If  the  upper  arch  has 
been  diminished  in  size 
through  extraction  the 
proper  procedure  would 
be  to  expand  it  to  the 
needed  extent  by  arch- 
wire  and  ligatures  and 
insert  artificial  teeth 
either  on  bridge  or  plate 
to  take  the  place  of  the  missing  ones. 

If,  in  the  enlargement  of  the  arch  the  incisal  edges  of  the 
anterior  teeth  assume  too  much  of  a  forward  slope,  as  they 
would  be  likely  to  do  if  the  forward  movement  were  great, 
it  will  be  necessary  to  move  their  roots  in  a  labial  direction 
also.  While  this  latter  operation  is  a  difficult  one,  necessi- 
tating the  construction  of  elaborate  apparatus,  it  may  be 
accomplished  after  the  manner  of  either  Dr.  Case  or  Dr. 
Knapp. 

The  appliance  of  Dr.  Case  is  shown  in  Fig.  149  and  full 

(199) 


Labial  Movement  of  Incisor  Roots  (Case). 


200 


ORTHODONTIA. 


FIG.  150. 


details  as  to  its  construction  will  be  found  in  the  American 
Text-Book  of  Operative  Dentistry,  pp.  833-841. 

It  consists  essentially  of  two  power  bars  passing  in  front 
of  the  teeth  to  be  moved  and  playing  in  tubes  attached  to 
the  buccal  surfaces  of  the  molar  anchor  bands.  One  of  the 
power  bars  rests  in  grooves  on  the  incisor  bands  near  their 
lower  edges  while  the  other  rests  in  grooves  on  the  inner 
side  of  a  short  extension  wire  attached  to  each  of  the  incisor 
bands  and  extending  well  up  under  the  lip  but  keeping 
clear  of  the  gum. 

The  first  power  bar,  by  virtue  of  its  position  and  by 
means  of  the  operating  nuts  on  the  ends  keeps  the  incisal 

edges  of  the  anterior  teeth 
from  moving  while  the 
operation  of  the  upper  bar, 
well  up  opposite  the  roots, 
forces  these  labially,  all  as 
shown  in  the  illustration. 
An  explanation  of  the 
exact  principle  upon  which 
the  device  operates  will  be 
found  on  pp.  66-69  of  this 
work. 

Of  the  mechanical  pro- 
trusion of  the  upper  in- 
cisor roots,  Prof.  Case  says : 
"  In  this  operation  it  will 
be  found  in  a  majority  of  cases,  and  especially  with  those 
which  are  begun  as  early  as  thirteen  or  fourteen  years  of  age, 
that  the  entire  intermaxillary  portion  of  the  upper  jaw  may 
be  carried  bodily  forward  with  the  roots  of  the  incisors."  By  a 
slight  change  in  construction  the  same  appliance  can  be  made 
equally  effective  inretruding  the  incisor  roots  or  in  holding 
them  in  position  while  either  protruding  or  retruding  the 
crowns. 

Dr.  Knapp's  device  for  protrusion  of  the  incisor  roots  is 
shown  in  position  in  Fig.  150. 


Device  for  Root  Protrusion  (Knapp). 


UPPER    RETRUSION*    WITH    LOWER    NORMAL. 


201 


FIG.  151. 


In  this  device  the  incisal  edges  are  immovably  held  by  a 
bar  passing  along  the  labial  surfaces  as  in  Dr.  Case's  appli- 
ance but  the  force  is  applied  at  the  necks  of  the  teeth  by 
means  of  an  arch-bar  running  along  the  lingual  surfaces  as 
close  as  possible  to  the  gum.  The  small  diagram,  Fig.  151. 
shows  more  clearly  the  principle  upon 
which  the  appliance  works. 

At  the  point  (39)  the  retaining  rod  rests 
in  a  groove  to  keep  the  incisal  edges  from 
moving  while  the  force  is  applied  at  B. 
The  result  will  be  the  moving  of  the  root 
at  A  in  the  direction  of  the  arrow. 

It  will  be  noticed  that  Dr.  Case's  device 
operates  upon  the  principle  of  a  lever  of 
the    second    class,   while    Dr.    Knapp's 
appliance   represents   a   lever   of  the   third   class.     Conse- 
quently a  great  application   of  force  will  be  necessary  to 
accomplish  the  desired  result  in  the  latter  case  than  in  the 
former. 


CLASS  V. 

LOWER  RETRUSION  WITH  UPPER  NORMAL. 

Cases  of  this  type  present  with  greater  frequency  than 
the  preceding  one.  It  is  easier  to  correct  because  the  lower 
jaw  can  be  moved  forward  much  more  readily  than  it  can 
be  retruded.  Fig.  152  represents  a  case  of  this  character  in 
which  the  lower  jaw  is  so  far  retruded  that  the  lower  teeth 

occlude     posterior 
FIG.  152.  * 

to  normal  the  full 

width  of  a  bicuspid 
tooth. 

The  remedy  lies 
in  the  mechanical 
protrusion  of  the 
lower  j  a  w  suffi- 
ciently to  bring 
about  benocclu- 
sion  of  upper  and 
lower  teeth.  The 
operation  of  mov- 
ing the  lower  jaw 
forward  so  as  to 

Lower  Retrusion  (Ainsworth). 

cause    t  h  e    lower 

teeth  to  occlude  one  step  in  advance  of  their  former  posi- 
tions has  come  to  be  known  as  "jumping  the  bite." 

It  may  be  accomplished  on  the  principle  of  the  inclined 
plane  or  by  means  of  the  intermaxillary  elastics.  Some- 
times a  combination  of  the  two  is  employed.  For  many 
years  the  inclined  plane  principle  was  embodied  in  a  vul- 
canite plate  fitting  the  vault  and  having  a  thickened  por- 
tion in  front  with  the  inclination  directed  forward.  This 
projection  was  so  fashioned  that  the  lower  incisors  could 

(202) 


LOWER    RETRUSION    WITH    UPPER    NORMAL.  203 

not  bite  back  of  it  and  when  they  came  in  contact  with  it 
they  glided  forward  carrying  the  entire  mandible  with 
them. 

In  most  cases  it  operated  successfully  and  in  the  course  of 
time  the  mandible  became  accustomed  to  its  new  position 
and  remained  there. 

FIG.  153. 


Inclined  Plane  in  Position  (Ainsworth). 

The  common  objections  to  the  use  of  a  vulcanite  plate 
caused  it  to  be  superseded  by  metal  inclined  planes  securely 
attached  to  the  upper  anterior  teeth. 

The  device  of  Dr.  Ainsworth*  is  an  excellent  represent- 
ative of  this  latter  class.  Fig.  153  shows  it  in  position. 

In  its  construction,  wide  metal  bands  are  fitted  to  the 
upper  central  incisors.  To  these  the  inclined  plane,  made 
from  hea,vy  platinous-gold  plate  is  adapted  and  soldered, 

*International  Dental  Journal,  July,  1904. 


ORTHODONTIA. 


while  lugs  of  half-round  gold  spring-wire  shaped  to  fit  over 
the  incisal  edges  of  the  laterals  are  also  attached. 

When  completed,  the  piece  is  cemented  in  position  to 

remain  until  the  lower 
jaw  has  established  itself 
in  its  new  position. 
This  may  require  from 
six  to  twelve  months, 
depending  upon  the  age 
of  the  patient. 

A  better  idea  of  the 
detail  of  construction  of 
the  Ainsworth  device  is 
conveyed  by  Fig.  154. 

When  the  intermax- 
illary elastics  are  to  be 
used  for  protrusion  oi  the  mandible,  arch-wires  should  be 
adjusted  to  the  upper  and  lower  teeth  in  the  usual  manner 
and  the  elastics  stretched  from  a  hook  attached  well  forward 
on  the  upper  wire  to  the  distal  end  of  the  tube  on  the  lower 
molar,  all  as  described  under  Class  2,  Section  C. 


Inclined  Plane  (Ainsworth). 


CLASS  VI 


FIG.  155. 


BIMAXILLARY  PROTRUSION. 

This  condition,  which  is  well  shown  in  Fig.  155,  is  quite 
an  uncommon  one,  and  the  author  has  never  seen  it  classi- 
fied or  treated  of  in  any  work  on  orthodontia.  But,  while 
rare,  it  is  occasionally  met  with  and  is  a  most  difficult  one 
to  treat.  The  etiology  of  it  is  hard  to  determine,  for  it  can- 
not be  referred  to  any  of  the  causes  which  usually  are 
responsible  for  dental  malposition. 

It  cannot  be  the  result  of  purely  mechanical  forces, 
because  the  upper  teeth,  if  protruding,  would  have  a 
tendency  to  hold  the 
lower  ones  in  posterior 
relation,  and  if  the  low- 
er teeth  had  forced  the 
upper  ones  outward 
they  themselves  would 
have  had  to  be  pro- 
truded in  order  to  do  so. 
While  we  have  no  data 
to  aid  us  in  forming  an 
opinion  as  to  the  cause 
of  the  peculiar  double 
malposition,  it  appears 
to  the  author  to  be  a  re- 
sult of  two  distinct  conditions.  An  examination  of  Fig.  156, 
which  is  a  vertical  view  of  the  two  arches,  shows  that  both  the 
upper  and  lower  arches  are  of  normal  size.  In  addition,  all 
of  the  anterior  teeth  both  above  and  below  are  spread  apart 
with  considerable  spaces  between  them.  In  fact,  this  fan- 
shaped  spreading  of  the  teeth  seems  to  be  a  constant  feature 
of  cases  of  this  character.  The  spacing  of  the  lower  teeth,  in 
spite  of  the  fact  that  they  are  overlapped  by  the  upper  ones, 

205 


Bimaxillary  Protrusion  (Weeks). 


206  ORTHODONTIA. 

would  seem  to  indicate  that  some  forces,  other  than  mechan- 
ical, were  instrumental  in  bringing  it  about.  The  natural 
inference  would  be  that  there  has  been  an  excessive  devel- 
opment of  alveolar  tissue,  especially  of  the  septa,  and  that 
this  has  forced  the  teeth  into  a  larger  curve. 

FIG.  156. 


Bimaxillary  Protrusion— Vertical  View. 

With  the  constant  forward  movement  of  the  anterior  teeth 
below,  the  upper  ones  would  naturally  be  carried  outward 
with  them. 

Fig.  157  represents  another  case  of  the  same  general  char- 
acter as  the  preceding  one.  Both  arches  are  of  more  than 


BIMAXILLAKY    PEOTEUSION. 


207 


FIG.  157. 


normal  size  with  spaces  between  all  of  the  anterior  teeth 
both  above  and  below,  and  the  lower  teeth  occlude  half  a 
space  posterior  to  the  upper  ones. 

The  treatment  of  this  type  of  irregularity  will  naturally 
involve  the  retrusion  of  the  upper  and  lower  anterior  teeth 
and  the  restoration  of  normal  occlusion.     The  lower  will 
have  to  be  retruded  first. 
This  can  best  be  done  by 
moving  them  in  pairs  by 
means  of  the  traction  screw 
shown  in  Fig.  19.     After 
the   cuspids   and    laterals 
have  been  moved  back  a 
bow  or  arch- wire  can  be 
adapted  and  the  centrals 
retruded. 

When  all  have  been 
moved  backward  and  the 
normal  arch  line  restored, 
with  all  of  the  teeth  in  con- 
tact, they  may  be  retained 
by  means  of  the  band  and 
wire  retainer  extending  from  cuspid  to  cuspid  as  shown  in 
Fig.  72.  The  upper  ones  can  then  be  retruded  in  the  same 
manner  and  retained  in  a  similar  way. 

In  this  and  all  other  cases  of  retention  of  the  anterior 
teeth  the  employment  of  many  bands  should  be  dispensed 
with  as  far  as  possible  on  account  of  the  space  they  occupy. 
Two  terminal  bands  joined  by  a  light  round  wire  constitutes 
the  best  retainer. 


Upper  and  Lower  Protrusion,  with  Lower 
Postocclusion. 


CLASS  VII. 

NONOCCLUSION. 

The  cause  of  this  deformity  like  that  of  many  others  has 
never  been  satisfactorily  determined.  It  maybe  due  to  the 
failure  of  certain  teeth  to  extrude  or  erupt  to  their  normal 
length ;  to  imperfect  or  mal-occlusion  ;  to  the  excessive 
extrusion  of  some  of  the  teeth  (usually  the  molars) ;  to  an 
over  obtuseness  of  the  angle  of  the  mandible ;  or  to  mouth 
breathing  and  the  presence  of  adenoids.  In  some  instances 
two  or  more  of  these  factors  may  be  operative  coincidently. 
The  condition  manifests  itself  in  three  forms : 
1.  Anterior  nonocclusion.  2.  Posterior  nonocclusion. 
3.  Lateral  nonocclusion.  The  latter  may  be  either  uni-  or 
bilateral. 

ANTERIOR  NONOCCLUSION. 

This  type  of  the  deformity  has  been  attributed  to  sleeping 
with  the  mouth  open  and  to  derangement  of  the  occlusion 
caused  by  ill-advised  extraction  of  some  of  the  posterior 
teeth  ;  but  while  these  may  be  responsible  for  the  condition 
in  certain  instances,  it  is  probably  more  frequently  caused 
either  by  the  lack  of  alveolar  development  in  the  incisor 
region,  or  by  an  unaccountable  variation  in  the  plane  of  the 
alveolar  border  of  the  mandible.  As  the  molars  and 
bicuspids  are  the  only  teeth  that  come  into  occlusion  in  this 
class  of  deformity,  it  would  seem  that  the  angles  of  the 
mandible  had  in  some  manner  become  more  obtuse  than  is 
normally  the  case. 

At  first  glance  the  incisors  have  the  appearance  of  being 
too  short  in  their  crowns,  but  an  examination  will  usually 
show  that  they  are  of  normal  size  and  length,  and  that  the 
process,  or  the  mandible  itself,  is  responsible  for  the  short- 
ened appearance. 

In  most  cases  it  will  be  found  that  both  arches  are  normal 
in  form  and  size,  and  that  there  is  no  protrusion  or  retru- 
sion  of  either  the  upper  or  lower  anterior  teeth. 

208 


NONOCCLUSION.  209 

TREATMENT. 

Three  methods  of  treatment  may  be  adopted  in  cases  of 
this  character: 

1.  Extrusion  of  the  nonoccluding  teeth.  2.  Pressure 
upon  the  anterior  portion  of  the  mandible.  3.  Shortening 
of  the  occluding  teeth  by  grinding,  accompanied  possibly  by 
devitalization  or  extraction. 

Extrusion  can  be  accomplished  in  the  safest  and  best  man- 
ner by  adopting  the  appliance  of  Dr.  Case  as  shown  in  Fig. 
136.  The  spring  of  the  wire  can  be  regulated  by  its  gauge 
and  the  curve  given  to  it,  and  its  operation  is  at  all  times 
under  control.  The  force  of  rubber  bands  or  elastics  cannot 
well  be  regulated  and  they  are  dangerous  in  consequence. 

Extrusion  should  only  be  resorted  to  when  the  crowns  of 
the  teeth  are  abnormally  short  and  where  the  nonocclusion 
is  slight  in  degree.  To  lengthen  them  greatly  would  be 
disfiguring,  and  they  would  be  all  the  more  difficult  to 
retain  in  their  extruded  positions. 

Retention  of  extruded  teeth  is  one  of  the  most  difficult 
tasks  that  confronts  the  orthodontist,  because  so  soon  as 
teeth  are  brought  into  occlusion  by  extrusion  more  or  less 
force  will  unavoidably  be  brought  to  bear  upon  them  in  the 
act  of  mastication,  and  to  successfully  resist  it  new  bony 
material  of  a  very  solid  character  must  have  been  formed  in 
the  alveoli. 

It  requires  weeks  and  sometimes  months  before  the 
extruded  teeth  can  be  left  without  any  retaining  appliance 
and  be  considered  firm  in  their  new  positions.  Even  after 
all  care  has  been  exercised  and  a  long  time  allowed,  the 
operator  is  often  mortified  to  find  the  teeth  again  receding 
into  their  sockets. 

Mandibular  pressure  is  the  most  rational  method  of  pro- 
cedure if  the  patient  be  not  over  twelve  or  fourteen  years  of 
age.  At  this  period  both  soft  and  hard  tissues  yield  readily 
in  response  to  pressure. 


210  ORTHODONTIA. 

Force  can  best  be  applied  to  the  mandible  by  means  of  a 
skull-cap,  chin-piece  and  rubber  bands,  as  described  and 
illustrated  in  a  preceding  chapter.  The  only  modification 
in  cases  like  this  being  that  the  force  must  be  applied  in 
an  almost  vertical  direction.  An  apparatus  of  this  charac- 
ter, worn  continuously  for  a  few  months,  would  tend  to  tip 
the  condyles  slightly  out  of  their  sockets,  and  allow  the  latter 
to  be  partially  filled  with  new  osseous  material.  The  change 
thus  produced  would  be  slow,  but  the  result  satisfactory. 

As  the  anterior  teeth  gradually  come  together  the  direc- 
tion of  the  force  should  be  so  regulated  as  to  cause  the  teeth 
to  come  into  normal  occlusion. 

Shortening  the  interfering  teeth  by  grinding,  is  often  neces- 
sary in  patients  over  twenty  years  of  age  if  a  satisfactory 
result  is  hoped  for.  Much  of  this  cannot  be  done  without 
denuding  the  teeth  of  their  enamel  at  certain  points  and 
exposing  the  sensitive  dentin,  but  by  grinding  as  much  as 
is  possible  without  causing  too  great  pain  and  then  anaes- 
thetizing the  tooth  by  means  of  cocaine  and  pressure,  quite 
an  improvement  can  be  brought  about. 

The  sensitiveness  of  the  exposed  dentin  may  be  obtunded 
afterward  by  repeated  applications  of  either  chloride  of  zinc, 
caustic  potash  or  nitrate  of  silver.  Where  these  are  not 
sufficient  it  will  be  advisable  to  devitalize  two  or  more  of 
the  teeth  most  interfering  with  occlusion  and  then  continue 
the  grinding  until  the  necessary  change  is  effected.  The 
devitalized  teeth,  of  course,  will  have  to  be  subsequently 
treated  and  filled. 

In  other  cases,  where  the  interference  of  one  or  two  teeth 
is  chiefly  responsible  for  the  condition,  extraction  may  be 
resorted  to.  In  some  instances  the  author  has  found  it 
necessary  both  to  extract  some  teeth  and  shorten  others  by 
grinding  in  order  to  obtain  even  a  moderate  degree  of 
improvement. 

Fig.  158,  taken  from  the  models  of  a  case  in  the  author's 
practice,  represents  this  condition.  In  addition  to  the  lack 


NONOCCLUSiON. 


211 


of  occlusion  all  of  the  six  anterior  teeth  above  and  below 
were  pitted  near  their  incisal  edges  due  to  imperfect  enamel 
formation.  The  arches  were  large  and  well  formed  and  all 
of  the  molars  abnormally  short  in  their  crowns. 

As  the  young  lady  was  twenty-seven  years  of  age  the  case 
could  not  be  treated  like  that  of  a  very  young  person.  The 
lower  anterior  crowns  were  of  nearly  normal  length  while 
the  upper  ones  were  but  a  little  less  than  normal. 

FIG.  158. 


Anterior  Nonocclusion. 

Sufficient  extrusion  to  bring  the  teeth  together  being  out 
of  the  question  and  mandibular  pressure  being  contraindi- 
cated  by  her  age,  shortening  by  grinding  appeared  to  be  the 
only  alternative  left.  This  was  done  very  gradually,  her 
appointments  being  a  week  apart.  By  the  use  of  obtundents 
and  pressure  anesthesia,  most  of  the  usual  pain  was  avoided 
except  in  one  or  two  teeth,  and  in  these  the  pulps  were  devi- 
talized to  permit  the  grinding  to  continue.  No  extraction 
was  resorted  to  because  it  was  avoidable,  and  because  a 
tooth  with  a  short  crown  is  better  than  no  tooth  at  all. 


212 


ORTHODONTIA. 


FIG.  159. 


The  entire  deformity  was  not  obliterated,  for  to  have 
accomplished  such  a  result  all  of  the  molar  teeth  would 
have  had  to  be  removed.  The  anterior  teeth,  however,  were 
brought  very  nearly  into  contact  and  the  patient's  appear- 
ance, speech  and  mastication  were  all  greatly  improved. 

A  somewhat  similar  case  in  which  both  arches  are  normal 
in  size  and  outline,  and  where  there  exists  a  simple  inabil- 
ity to  effect  a  closure  of  the  jaws  in  front,  is  shown  in  Fig. 
159.  Dr.  Quattlebaum  writes : 

"  The  patient  was  a  strong,  healthy  girl,  fifteen  years  of  age, 
and  no  cause  for  the  deformity  could  be  discovered.  The 

second  molars  on 
each  side,  above 
and  below,  are  the 
only  ones  that 
come  into  occlu- 
sion; and  while 
thefirst  molarsand 
bicuspids  are  near- 
ly in  contact,  the 
anterior  teeth  are 
quite  wide  apart 
when  the  jaws  are 
closed." 

In  a  case  like  this,  where  the  contraction  or  non-expansion 
of  the  upper  arch  was  evidently  caused  by  the  extraction 
of  one  or  more  of  the  bicuspids,  the  arch  should  be  enlarged 
and  the  spaces  resulting  from  the  extraction  should  be  filled 
by  artificial  substitution.  Then,  at  the  patient's  age,  man- 
dibular  pressure  might  result  in  intruding  the  molars  and 
bringing  the  anterior  teeth  into  occlusion.  Possibly  some 
grinding  of  the  molars  might  also  be  necessary. 

POSTERIOR  NONOCCLUSION. 

This  very  unusual  condition  is  most  probably  brought 
about  by  the  gradual  forward  movement  of  the  mandible 
until  the  incisors  meet  edge  to  edge,  but  why  this  movement 


Lack  of  Anterior  Occlusion  (Quattlebaum). 


XONOCCLUSION. 


213 


should  take  place  when  the  upper  teeth  probably  origin- 
ally overlapped  them  we  cannot  conceive.  Fig.  160  is  a  good 
illustration  of  the  deformity.  "  The  patient  was  a  young 
lady  sixteen  years  of  age,  and  when  she  presented  the  right 
superior  central  incisor  was  the  only  one  of  the  superior 

incisors   that  oc- 

,    i    -,       .  ,  ,     ,,  FIG.  160. 

eluded  with   the 

lower." 

In  the  treatment, 
the  upper  arch  was 
widened  so  as  to 
bring  the  upper  bi- 
cuspids and  mo- 
lars directly  over 
the  lower  ones  in 
normal  position, 
after  which  the  up- 
per incisors  were 
moved  labially  to  allow  a  better  closure  of  the  jaws.  Even 
with  this  accomplished  the  molars  and  bicuspids  were 
still  in  nonocclusion,  so  that  the  lower  ones  had  to  be 
crowned  to  bring  them  into  occlusion.  Gold  shell  crowns 
were  adapted  to  the  molars,  while  gold  bands  with  por- 
celain occluding  portions  were  fitted  to  the  bicuspids. 
The  resulting  occlusion  was  not  quite  normal,  but  entirely 
serviceable. 

Fig.  161  represents  the  case  after  correction. 

"A  very  small  vulcanite  retaining  plate  was  worn  to  hold 
the  upper  teeth  in  position." 


Posterior  Nonocclusion  i  Willis  i. 


LATERAL  NONOCCLUSION. 


This  form  of  irregularity  usually  obtains  on  one  side  of 
mouth  only,  and  it  may  involve  the  bicuspids  or  both  molars 
and  bicuspids.  When  the  bicuspids  alone  are  the  ones  out 
of  occlusion  they  can  be  extruded  very  easily  by  the  use  of 


214 


ORTHODONTIA. 


intermaxillary  elastics  as  shown  in  a  case  reported  by  the 
late  Prof.  Goddard.     Describing  his  method  he  says : — 

"  Bands  with  hooks  are  attached  to  both  upper  and  lower 
teeth  and  a  rubber  ring  stretched  from  each  upper  hook  to 


FIG.  161. 


Corrected  Case. 


the  corresponding  lower  one,  or  the  place  of  either  upper  or 
lower  band  may  be  supplied  by  a  ligature. 

"  The  patient  should  unhook  each  ring  while  eating,  and 
readjust  it  afterward." 


FIG.  162. 


Lateral  Nonocclusion  (Goddard). 

"  Fig.  162  represents  the  case  before  and  after  correction 
together  with  the  appliances  used." 

A  case  of  unilateral  nonocclusion  in  which  all  of  the 
teeth  posterior  to  the  cuspids  on  one  side  were  involved,  was 
referred  to  the  author  for  advice  some  years  ago. 

Fig.  163  is  made  from  a  photograph  of  the  models. 

As  will   be  noticed,  it  is  a  case  of  combined  lateral  and 


NONOCCLUSION.  215 

posterior  nonocclusion,  and  while  the  buccal  teeth  seem  to 
be  fully  erupted  their  occlusal  surfaces  are  far  apart. 

It  would  be  difficult  to  make  even  a  suggestion  as  to  the 

FIG.  163. 


LateraKand  Posterior  Nonocclusion. 


cause  of  this  unique  condition,  and  there  would  seem  to  be 
but  one  rational  method  of  treatment,  i.  e.,  crowning  the 
affected  teeth. 

It  is  the  only  case  of  the  kind  that  the  author  has  ever  seen. 


INDEX. 


217 


I  N  E>  EX. 


Accidental  injury  as  a  cause  of 
irregularity,  21. 

Acquired  irregularities,  13. 

Adenoid  vegetation  as  a  cause  of 
irregularities,  21,  179. 

Adjustable  bow-spring,  175. 

Age,  consideration  of  in  correction 
of  irregularities,  37. 

Ainsworth,  Geo.  C.,  methods  of  regu- 
lating, 119,  202. 

retainer,  132. 

Alveolar  process,  physiology  of,  49. 

Anchorage  attachments  in  tooth 
movements,  58,  64. 

intermaxillary,  64. 

Anchorage,  band  and  screw,  61. 

occipital,  65. 

reciprocal.  68. 

re-enforced,  60. 

Angle's  regulating  methods,  62,  106, 
165,  170,  188. 

—  retainer,  170. 

—  retraction  appliances,  188. 
Anterior  n on  occlusion,  211,  212. 
Anterior  protrusion,  24. 

—  teeth,  malposition  of,  172. 
Appliances,  essential  qualities  of,  83. 
Arch,  expansion  of,  174,  176. 

—  crowded  lower,  178. 

—  constricted,  28. 
-  Gothic,  22,  26. 

Articulated  models,  usefulness  of ,  81. 
Articulator,  Guilford's,  80. 

Band  and  bar  retaining  appliances, 

129,  131. 
Band  and  screw  anchorage,  61. 

—  and  wire  retainer,  130. 

Bands,  retaining,  construction  of ,  101. 

—  use  of  in  moving  teeth,  60,  146, 

214. 

Benocclusion,  defined,  33. 

Bicuspids,  extraction  of  for  regula- 
tion purposes,  46. 


Bimaxillary  protrusion,  205. 
Bite  Plate,  vulcanite,  183. 
Buccal  malocclusion,  177. 

Canning's      regulating     appliances, 

110.   153,  176. 

Cap  crown,  construction  of,  102. 
Case's  retainer,  131. 

—  regulating  devices,  64,  161,  184, 

192,  199. 

Cells  of  construction  and  destruction 
of  the  pericementum,  52, 

Cementoblasts,  52. 

Centrals,  torsion  of,  38. 

China-grass  line,  use  of  in  regulat- 
ing, 92. 

Cleanliness,  maintenance  of  in  regu- 
lating appliances,  85. 

Coffin  Lemuel,  expansion  method, 
110,  114. 

—  W.  H.,  regulating  methods,  146, 

149. 

College,  orthodontia  technics  in,  135. 

Combination  appliances  for  expan- 
sion, 175. 

Compressed  wood  for  regulating  ap- 
pliances, 90. 

Conditions  governing  correction,  37. 

Constricted  arch,  28. 

Correction,  advisability  of,  37. 

Cortical  layer  of  maxillae,  peculiarity 
of,  73. 

Crib,  Jackson's,  61,  115,  116. 

Curved  spring  and  bands  device,  143. 

Cuspid,  abnormal  eruption  of,  46. 

—  regulation  of,  152. 

—  temporary,  evil  results  of  extrac- 

tion of,  16,  38. 

Deciduous  teeth,  early  extraction 
of,  15. 

irregularities  of,  15. 

long  retention  of,  13. 


218 


INDEX. 


Deformity  of  the  face  due  to  pro- 
trusion, 179 

Dentition,  completion  of  before  oper- 
ation, 40. 

Double  torsion   164,  168. 

Drag-screws,  99. 

Dynamics  of  tooth -movement,  58. 

Early  interference,  when  justifiable, 
40. 

Elasticity  in  regulating  appliances, 
70,  91,  192. 

Eruption,  incomplete,  162. 

Essential  qualities  in  regulating  ap- 
pliances, 83. 

Expansion  by  screw,  174. 

Expansion  devices  for  regulating, 
119,  174. 

—  method,  Coffin's,  113. 
Extraction  as  related  to  orthodontia, 

14,  16,  17,  38,  42. 
Extrusion  of  teeth,  56,  157,  184. 

Facial  appearance,  marring  of  by 
irregularities,  31. 

—  deformities  from  protruding  jaws, 

179. 

—  harmony  and    occlusal  relation, 

30. 

Family  types  of  jaws,  13. 
Farrar,  J.   N.,  regulating  methods, 

1C6,  188. 

Faulty  occlusion,  35. 
Ferrules,  construction  of,  102. 
First  permanent  molars,  extraction 

of,  43,  46. 

Fixed-plane  device  in  regulating,  145. 
Force,  proper  application  of,  65,  82. 

—  results  of  on  tooth  movement,  54. 

German  silver  for  regulating  appli- 
ances, 89,  105. 

Goddard's  regulating  devices,  143, 
160,  174,  188,  214. 

Gold,  use  of,  in  regulating  devices,  87. 

Gothic  Arch,  26. 

Guilford's  band  and  bar  retainer, 
129. 

—  case  of  nonocclusion,  210. 

—  regulating  appliances,    158,   168, 

189. 

—  taps  and  die,  96. 

Habits,    bad,    irregularities   caused 

by,  22. 
Hard-soldering,  suggestions  for,    99. 


Health,  consideration  of  in  correction 

of  irregularities,  40. 
Hereditary  irregularities,  12 
Hooked  bands,  construction  of,  103. 

Impression  materials,  75. 

—  taking,  75,  135. 

—  trays,  best  form  of,  75. 

Ill  results    of    over-application    of 

force,  191. 
Incisors,  device  for  retrusion  of,  189. 

—  extrusion  and  retrusion  of,  184. 

—  lingual  misplacement  of,  173. 

—  lower,  regulating  plates  for,  144, 

149,  195. 

—  mesial  movement  of,  156. 

—  protrusion  of,  179. 

—  regulation  of,  199. 

—  result  of  delayed  extraction  of,  14. 
Inclined-plane  plates  for  moving  in- 
cisors, 144,  195. 

principle  in  tooth  movement, 

203. 

Indented  expansion  arch,  177. 
Incomplete  eruption,  162. 
Injuries,   accidental,   as  a  cause  of 

irregularities,  21. 
Interdental  space,  abnormal,  13. 
Intermaxillary  anchorage,  64. 
Intrusion  of  teeth,  57,  159,  184. 
Iridio-platinum,  use  of  in  regulating 

appliances,  88. 
Irregularities,  classification  of,  139. 

—  Complex,  172. 

—  etiology,  of,  12. 

—  evils  resulting  from,  26. 
Irregularity,  definition  of,  10. 

Jack-screw  in  regulating,  174. 

Jackson,  V.  H.,  method  of  regulat- 
ing, 115. 

Jackson's  regulating  devices,  115, 
119. 

Jaw,  lower,  protrusion  of,  194. 

Jumping  the  bite,  202. 

Kingsley's  regulating  method,  188. 
Knapp's  regulating  appliances,  108, 

149,  153,  166,  178,  200. 
method   of   extrusion   and   in- 
trusion, 185. 

Lateral  non-occlusion,  213. 
Lever,  principle  in  tooth  movement, 
66,  68. 


INDEX. 


219 


Leverage,  principles  of,  for  moving 

roots,  201. 

Ligatures,  use  of  in  regulating,  92. 
Lip-sucking,     influence    of    on    the 

teeth,  22. 

Lower  arch,  expansion  of,  175. 
Lower  jaw.  protrusion  of.  194. 
—  teeth,  protrusion  of,  181. 


Magill  band,  129,  147,  159. 
Malooclusion,  bilateral,  178. 

—  unilateral,  178. 
Malocclusion  denned,  35. 
Malposition,  labial  or  lingual,  142. 

—  of  anterior  teeth,  172. 
Mandibular  pressure  in  regulation, 

209. 

—  protrusion,  197. 
Matteson  caps,  102. 

Matteson's  regulating  devices,  146. 
Mechanical     powers     employed    in 

tooth-movement,  69. 
Mesial  and  distal  malposition,  151. 
Mills,  W.   A.,  case   of    irregularity 

from  adenoid  growth,  22. 
Modeling  compound  for   impression 

taking,  77. 

Models,  importance  of,  78,  135 
Molars,  extraction  of  for  regulating, 

43. 
Mouth,  examination  of,  74. 


Nasal  growths,  irregularities  caused 

by,  21. 

Needless  extraction,  48. 
Nonocclusion,  208 
Xon occlusion,  treatment  of,  209. 
Xormal  buccal  occlusion,  173. 
Nuts,  construction  of,  99. 


Occipital  anchorage,  65. 

—  resistance,  appliance  for,  65. 
Occlusion,  definition  of,  33. 

—  importance  of  to  mastication,  35. 

—  lack  of,  208. 

—  typical,  34. 
Opening  the  bite,  185. 
Orthodontia  as  a  specialty  of  dentis- 
try, 9. 

—  college  cousre  in,  outlined,  134. 
Osteoblasts,  52. 

Overlapping  of  teeth,  14. 


Patients,  avoidance  of  discomfort  to, 

40. 

Pericementum,  physiology  of, 51. 
Permanent  teeth,  delayed  eruption 

of,  18. 

eruption  of,  15. 

injudicious  extraction  of,  17. 

Physiology  of  tooth  movement,  49. 

Piano  wire,  bending  of,  101. 

for  regulating,  110,    115,  146, 

171. 
Plaster   models,   construction  of,  78, 

135. 

Plaster  of  Paris  for  impressions,  75. 
Plate  and  wire  retainers,  128,  170. 
Plate,  use  of  in  regulating,  195. 
Platinoid,  89. 
Platinons  gold,  87. 

—  silver,  88. 

Platinum,  use  of  in  regulating  appli- 
ances, 88. 

Posterior  occlusion,  lack  of,  213. 

Power  required  for  tooth  movement, 
71. 

Practical  considerations,  74. 

Prognathism,  26 

Protrusion,  anterior,  24. 

—  bimaxillary,  205. 

—  lower,  26,  194,  197. 

—  of  lower  jaw,  treatment  of,  195. 
-  upper  24,  179,  180,  181, 182,  183, 

Pulp,  physiology  of,  51. 

Quattlebanm,  Dr.,  case  of  maloccln- 
sion,  212. 

Racial  intermarriage  as  a  cause  of 

irregularities,  13. 
Reciprocal  anchorage,  63. 
Regulating  appliances,  construction 

of,  87. 

qualities  essential  to,  83. 

Regularity,  definition  of,  10. 
Resistance,    character    of    in    tooth 

movement,  70. 

Resorption,  aid  in  regulating,  72. 
Retaining  appliances,  127,  128,  131. 

170. 

Retraction  appliances,  152,  153,  188. 
Retrusion  appliances,  188. 

—  cases  of,  182,  183,  189,  196,  202. 
Roots,  movement  of,   independent  of 

crowns,  199. 

Rotating  devices,  165,  167,  168,  170. 
Rotation  of  teeth,  163,  167. 


220 


INDEX. 


Rubber,  elastic,  use  of  in  regulating, 
91,  152,  155. 

—  vulcanite  plates,  use  of  as  retain- 

ing appliances,  128,  170. 

—  vulcanite  retaining  plate,  128,  170. 

Saddle  regulating  device,  144. 
Hcrew,  expansion  by,  174. 

—  principle  in  tooth  movement,  70, 

149. 

Screws,  construction  of,  98. 
Separation,  Goddard's  appliance  for, 

143. 
Sex,  consideration  of  in  correction  of 

irregularities,  41. 
Side  crib,  Jackson's,  116. 
Simplicity  in  regulating  devices,  84. 
Skull  Cap,  Guilford's.  190. 
Soft  soldering,  method  of,  100. 
Soldering,  99,  100. 

—  clips,  101. 

Spring  bar  and  band  for  rotation, 
148. 

Stability,  importance  of  in  regulat 
ing  appliances,  86. 

Steel,  use  of,  for  regulating  appli- 
ances, 90. 

Stock  material  and  appliances,  104, 
106. 

Supernumerary  teeth,  18. 

Teeth,  anterior,  malposition  of,  172. 

—  deciduous,  long  retention  .of,  13. 
early  loss  of,  15.  ^ 

—  delayed  eruption  of,  14. 

—  extrusion  of,  56,  157,  184. 

—  non-occlusion  of,  208. 

-   normal   arrangement   of    in   the 
dental  arch,  10. 

—  permanent,  delayed  eruption  of, 

18. 
eruption  of,  15. 

—  premature  extraction  of,  15. 

—  regulation  of  for  superior  protru- 

sion,  183. 


—  retention  of  in  situ  after  moving, 
127. 

—  rotation  of,  163,  167. 

—  shortening  interfering,  210. 

—  supernumerary,  18. 

—  torsion  of,  163,  168,  170. 
Thumb-sucking,  influence  of  on  the 

teeth,  23. 
Tissue  changes  subsequent  to  tooth 

movement,  56. 

Tomes,  C.  on  the  Gothic  arcb,  27. 
Tools  for  construction  of  regulating. 

appliances,  93. 
Tooth  movement,  dynamics  of,  58. 

physiology  of,  49. 

Tooth  pulp,  physiology  of,  51. 
Torsion,  163,  168,  170. 

—  causes  of,  163. 

Tube,  band  and  spring  appliancey 
146. 

Tubing,  French  rubber,  91. 

Tubing,  regulating,  construction  ofr 
97,  104. 

Tucker,  E.  G. ,  introduction  of  rub- 
ber tubing,  91. 

Upper  arch,  general  expansion  of,. 
174. 

—  protrusion,  179. 

Vulcanite  bite-plate,  183. 

—  plate   with   piano   wire    springs, 

148. 

—  use  of  for  regulating  appliances,. 

92. 

Weeks,  bimaxillary  protrusion,  205. 
Wedge  principle  in  tooth  movement, 

70. 
Willis,  Dr.,   case  of  non-occlusion r 

213. 

Wire  and  band  appliance,  116. 
Wire  bending,  100. 
Wire  articulator,  80. 
Wire  drawing,  process  of,  97. 
Wire  spring,  regulating  device,  116- 
Wood,  compressed,  in  regulation,  9O_ 


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